Category Archives: EvoPsych

What Should We Mean When We Say “Universal”?

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My last post prompted a series of spirited discussions, each of which I found interesting for slightly different reasons. Over the course of one of those discussion, a commenter over at Psychology Today (H/T to Anthro_girl) referred me to an article entitled “Darwin in mind: New opportunities for evolutionary psychology” (Bolhuis et al. 2011). I haven’t yet decided if I this will turn into a series of posts on the ideas presented in that article, but there is one point in particular I would like to focus in on for the current purposes, and it’s entirely semantic in nature: what the term “universal” ought to mean. Attempts on clearing up semantic confusion tend to be unproductive in my experience, but I think it’s important to at least give these matters a deeper consideration, as they can breed the appearance of disagreement, despite two parties saying essentially the same thing (what has been previously called “violent agreement“, and I think represents the bulk of the ideas found in the article).

“You’re absolutely right and I respect your position, which is also my own!”

The first point I would like to mention is that I find Bolhuis et al’s (2011) wording quite peculiar: they seem to, at least at some points, contrast “flexibility” with universality. It sounds as if they are trying to contrast “genetic determinism” with flexibility instead, which seems to be a fairly common mistake people make when criticizing what they think evolutionary psychology assumes. Since that point is a fairly common misunderstanding, there’s little need to go over it again here, but it does give me an opportunity to think about what it means for a trait to be universal, using their example of sexual selection. The authors suggest that as a number of environmental cues (encounter rates, cost of parental investment, etc) change, so too should we expect mating strategies to change: change the inputs to a system, change the outputs. Now nothing about that analysis strikes me as particularly incorrect, but the implication that follows it does: specifically, a universal trait ought not to show much, if any, variation. Well, OK, they don’t really imply it so much as they flat-out say it:

“Arguably, the more flexible and variable the exhibited behaviour, the less explanatory power can be attributed to evolved structure in the mind.”  

Their analysis seems to misstep in regard to why those other variables might matter in determining variation. In order for variables, like encounter rates or the likely costs of parental investment, to matter in the first place, some other psychological mechanisms need to be sensitive to those inputs; other evolved structures of the mind. If no evolved structures are sensitive to those inputs, or the structures which are sensitive to those variables aren’t hooked up to the structures that determine sexual behavior, there wouldn’t be any consistent effect of their presence or absence. Thus, finding variation in a trait, like sexual selectively, doesn’t tell you much about whether the mechanisms involved in determining said behavior are universal or not. This does, however, raise in inevitable question about universality: do we need to expect a near-perfectly consistent expression of a trait in order to call it universal?

I would think not. This gets at a distinction highlighted by Norenzayan & Heine (2005) between various types of universality, specifically the “functional” and “accessible” varieties. The functional type refers to traits that use the same underlying mechanisms and solve the same kinds of problems (so if people in all cultures use hammers to beat in nails, hammers would be functionally universal); the accessible type is the same as the functional type, only that it is used to pretty much the same degree across different cultures (all cultures would need to use their hammers approximately the same amount). In other words, then, different cultures might differ with respect to how sexually selective men tend to be relative to women, but in all people there are still the same underlying mechanisms at work and they are still used to solve the same kinds of problems, so we can still feel pretty good about calling that difference in sexual selectivity a universal. While that’s all well and good, it does create a new problem, though: how much variation counts as “a lot of it”, or at least enough of it to warrant one classification or the other?

Fairly mundane for basketball, but maybe the most exciting soccer match ever.

Two examples should help clear this up. Let’s say you’re a fairly boring kind of researcher and find yourself examining finger length cross-culturally, trying to determine if finger length is universal. You get your ruler out, figure out a way to convince thousands of people the world over to let you examine their hands in dozens of different languages, and locate a nice grant to cover all your travel costs (along with the time you won’t be spending doing other things like teaching or seeing your friends and family). After months of hard work, you’re finally able to report your findings: you have found that middle fingers are approximately 2.75 inches in length and, between cultures, that mean varies between 2.65 inches and 3.25 inches. From this, are we to conclude that middle finger length is or is not universal?

The answer to this question is by no means straight forward; it seems to be more of an “I know it when I see it” kind of judgment call. There clearly is some variation, but is there enough variation there to be meaningful? Would middle fingers be classified as a “functional” universal or an “accessible” universal (if such labels made sense in case of fingers, that is)?  While the finger might seem a bit strange as an example, it has a major benefit: it involves a trait that is rather easy to find a generally agreed upon definition and form of measurement. Let’s say that you’re interested in looking at something a more difficult to assess, like the aforementioned sexually selectively. Now all sorts of new questions will come creeping in: is your test the best way of assessing what you hope to? Is your method one that is likely to be interpreted in a consistent manner across cultures? The initial question still needs to be answered as well: how much variation is enough? If the difference in sexual selectively between men and women is twice as large in culture A, relative to culture B, does that make it a functional or an accessible universal? What is that difference was only 1.5 times the size from culture to culture, or 3 times the size? From what I could gather, there really is no hard or fast rule for determining this, so the distinction might appear to be more arbitrary than real.

While these are all worthwhile questions to consider and difficult ones to answer, let’s assume that we were able to provide answers to them, in some form and find that sexually selectively, while functionally universal, is not what we would consider an accessible universal (that is there is a significant amount, whatever that happens to be, of variance between cultures in its size). While the variance you turned up is all well and good, what precisely is that variance a product of? There are many cognitive mechanisms that play a role in determining sexual selectivity, and our finding that sexual selectively isn’t an accessible universal doesn’t answer the question as to which components that determine that trait are or are not accessible universals. Perhaps approach rate is an accessible universal, but the male/female ratio in a population is only a functional universal. This could, in particular cases, even lead us to some odd conclusions: if one of the mechanisms that helps determines sexual selectivity isn’t an accessible universal in that instance, it might well be considered an accessible universal in another where its output is used to determine some other trait. For instance, hypothetically, sex ratio might not be an accessible universal when it comes to sexual selectivity, but could be one when it comes to determining some propensity for violence. In other cases, sex ratio might be a functional or accessible universal, but only depending on what test you’re using (on a Likert scale, it might only be functionally universal; in a singles bar, it might be accessibly universal).

Riveting as I’m sure you all find this, I’ll try and wrap it up.

So, as before, attempts to clear up semantic confusion have not necessarily been successful. Then again, if matters like this were simple, it’s doubtful that these kinds of disagreement would have cropped up in the first place. Hopefully, some the issues between focusing on the outputs of mechanisms versus the mechanisms themselves have at least been highlighted. There are two final points to make about the idea of universality: first, if there was no underlying universal human nature, cross-cultural research would be all but impossible to conduct, as foreign cultures would not be able to be understood at all in the first place. Secondly, that point is demonstrated well by what I would call cross-cultural cross-fostering. More precisely, as Norenzayan & Heine (2005) note, when infants from other cultures are raised in a new one (say an Asian family immigrates to America), within two or three generations, the children of that family will be all but indistinguishable from their “new” cultural peers. Without an underlying set of universal psychological mechanisms, it’s unclear precisely how such adaptation would be possible.

So yes, while WEIRD undergraduates might not give you a complete picture of human psychology, it doesn’t mean that they offer nothing, or even very little. The differences between cultures can hide the oceans of similarity that lurk right underneath the surface. It’s important to not lose sight of the forest for a few trees.

References: Bolhuis JJ, Brown GR, Richardson RC, & Laland KN (2011). Darwin in mind: new opportunities for evolutionary psychology. PLoS biology, 9 (7) PMID: 21811401

Norenzayan, A., & Heine, S. (2005). Psychological Universals: What Are They and How Can We Know? Psychological Bulletin, 131 (5), 763-784 DOI: 10.1037/0033-2909.131.5.763

 

Is It Only “Good” Science When It Confirms Your World View?

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Most people, when critical of some finding or some field, try to do things like keep their biases hidden, opting instead to try and argue from a position of perceived intellectual neutrality. Kate Clancy, evidently, is not most people. In her recent post at Scientific American, she lays it all out there, right in the title: “5 Ways to Make Progress in Evolutionary Psychology: Smash, Not Match, Stereotypes“. So, there you have it: if evolutionary psychology wants to progress as field, the practitioners ought to ensure we are getting results that Kate finds to be personally palatable so, rather than run experiments, we ought to just ask her what she likes instead. I can only imagine how much time and money this will save us all when it comes to collecting data and getting through the review boards, never mind all that pesky theory development. Of course, her suggestion for progression in the field might not be useful when it comes to developing and testing hypotheses about subjects that aren’t (heavily) stereotyped, but, in all fairness, her suggestion isn’t likely to be helpful in any case at all.

“Sure, it might not run, but at it does that 100% of the time!”

Thankfully, Kate is willing to suggest five more specific criticisms of where she thinks evolutionary psychology stands to be improved. I’m sure that her criticisms here will be enlightening for all the evolutionary psychologists, as the alternative – that she’s proposing things which have already been repeatedly acknowledged and cautioned against by every major researcher in the field from its inception – would probably be pretty embarrassing for her. Sure, the critics of evolutionary psychology have been known to be ignorant of the field they’re criticizing as a general rule, but stereotypes aren’t always true. Hopefully Kate will, like any good scientist should, according to her, bust that stereotype, demonstrating both her fluency in understanding the theoretical commitments of the field and also pointing out their deficiencies. Since I’m a non-progressive evolutionary psychologist, this leaves me stuck with the grim task of confirming the stereotype that critics of my field tend to, in fact, know very little about it. Five rounds and one issue: the progression of evolutionary psychology as a field.

Round 1: [Evolutionary Psychologists] aren’t measuring what we think we are.

The point here is that evolutionary psychologists sometimes use proxy measures to measure other variables. So, for instance, if you want to study some theoretical construct like, say, “general intelligence”, you might use the results of some other test, like an IQ test, to draw inferences about the initial construct (people who score high on the IQ test have a lot of general intelligence). Now there’s nothing wrong with pointing out the fact that these proxy measures might not be tapping the underlying construct that you think they are, nor is it particularly problematic to point out that the underlying construct you think you’re measuring might not even exist. I’m fine with all that. Where I get lost is when I consider what any of it has to do with evolutionary psychology, specifically. Are evolutionary researchers worse at creating or using proxy measures? Does this point speak to the theoretical foundations of evolutionary psychology in any way? Since Kate provides no evidence to help answer the first question, I’ll assume that answer is probably a no (unless Kate is just stereotyping evolutionary researchers as poor in this department). Since proxy measures in no way at all speak to the theoretical commitments of the field itself, this entire point seems rather misguided. If she was talking about the field of psychology more generally, sure, this is a research pitfall to avoid; it’s just not one specific to my field. Round one goes to stereotype confirming evolutionary psychology.

Round 2: Undergrads only teach us about undergrads.

Kate’s criticism here comes in two parts: concerns for generalizability across samples and concerns that undergraduates can’t tell us anything useful about human psychology. Taking them in order, in psychology more generally there is a reliance on undergraduate samples, mainly because they’re cheap and convenient. The problem, though, is that the results of research on some of these undergraduates (typically those taking introductory to psychology, no less), might not tell us much about people who differ from them, either in age, race, education, nationality, social life, etc. On that account, Kate is indeed correct: there might or might not be problems in generalizing from handfuls of undergraduates to the human race more generally. Again, however, this criticism runs directly into the same hurdle her last one did: it’s not specific to any of the theoretical commitments of evolutionary psychology. The problem here is one faced by psychology more generally and, if anything, the people who tend to realize the importance of cross-cultural as well as cross-species research tend to be evolutionary people, at least in my experience.

Her second point, however, is even worse. Kate seems to go from undergraduates might not be able to tell us much about the human species to undergraduates definitely do not tell us anything useful, or, as she puts it, are “about as far removed from the conditions in which we evolved as you can get“. What Kate fails to recognize is that, in the vast majority of respects, these undergraduates are very similar to people everywhere else: they form relationships, both sexual and social, they discriminate between potential mates, they reason, they morally condemn others, they defend against moral condemnation, they eat, they sleep, they reciprocate, they punish non-reciprocation, they learn language, and so on. Focusing on a few superficial differences between groups of people can, it seems, make one miss the oceans of similarity between them. Just because undergraduates aren’t living as hunter-gatherers, it does not follow that they have nothing useful to tell us about human psychology. Round two also goes to stereotype confirming evolutionary psychology.

Three more rounds to go. I’m sure you’ll turn it around…

Round 3: It’s not true that everything happens for a reason.

This charge is a classic one: there’s more to evolution than selection; there are also byproducts, drift, and mutation and those evolutionary psychologists need to recognize this! In Kate’s example, for instance, evolutionary psychologists might make up adaptive stories about her choice of sock color. If that was the state of evolutionary psychology, we truly would be a field in need of scolding. Now I could point out that, a little over two decades ago, in what might be considered the foundational text of the field, the byproduct, drift, and mutation issues are all discussed, and every major figure in the field has, at many points, explicitly acknowledged the role of these forces (see here, specifically charge 2) and leave it at that. I could also point out, as I have done before, that predictions derived from hypotheses of drift don’t tend to make very useful predictions. However, there are two additional points to not miss.

First, suggesting that psychological traits have adaptive functions is a step up from most non-evolutionary psychology, which tends to either posits unless functions (i.e. self-esteem or ego defense) or no functions at all. In this regard, evolutionary psychology is better, not worse, for it. Secondly, and more importantly, Kate gets a lot wrong in this section. Her initial point about how not all behaviors are the result of psychological adaptations misses the point entirely. Her behavior – choice of sock color, in this case – might not be the result of a specific module designed with the function of choosing sock color, but it would be a mistake to, from that, conclude it wasn’t result of other psychological adaptations. This would be as silly as my concluding that, because my body didn’t evolve to eat pop-tarts, my ability to digest them must not be a result of any physiological adaptations designed for digestion. On top of this misunderstanding, she then goes on to suggest that adaptations are heritable, by which she means some variation in them must be due to unique genetic factors. Under this logic, hands aren’t adaptations, because variation in having hands tends to not have a heritable genetic component (as well pretty much all do have hands). Anyone familiar with adaptationist logic will tell you pretty much the opposite: many adaptations – like livers and hands – tend to show very low heritability, because selection tends to remove heritability from the population. Round three is over, and it’s not looking so good for stereotype disconfirmation.

Round 4: There is more than one way [to reproduce]

This point suggests that, apparently, evolutionary psychologists have yet to realize that there’s more than one successful strategy that people can adopt when it comes to reproduction. We apparently don’t realize that there are many possible routes to take, and variable degrees of taking them. This is not only false; it’s stunningly false. In fact, in the next paragraph, Kate mentions that, sure, evolutionary psychologists have done research on some of these different, competing strategies, but it apparently wasn’t up to her standards. If she prefers a more nuanced view than the one she (likely incorrectly) perceives in the people doing research concerning whether one is more of a cad or a dad, she’s more than welcome to it. The researchers in the field would, if her view is better or has something they missed, happily accept the contribution. Were she to offer her view, however, my guess is that she’ll end up publicly disagreeing with an opinion that no serious researcher holds; basically what she is doing here. However, to imply, as she does, that evolutionary researchers don’t appreciate and attempt to understand variation, is just plain stupid, especially right after she points out that evolutionary psychologists already do it.

Kate then seems to try and say something about homosexuality, but, I admit, her point there is lost on me. It might be something along the lines of, “people who identify as non-straight sometimes have children, so there’s nothing to see here”, but I’ll admit that I’m having a hard time following what she’s trying to say, much less what the relevance would be. Round four, unsurprisingly, isn’t going to Kate.

Round 5: Just because [it's currently adaptive, that doesn't mean it previously was]

The only point I really want to make here is noting that Kate gets the definition of the environment of evolutionary adaptedness (EEA) dead wrong. As anyone familiar with this concept, or the primer on the subject, can tell you, the EEA is not a time or a place (much less on a savannah where everyone lived happily, as Kate seems to think it is), but the statistical aggregate of selective forces that shaped an adaptation. Thus, the EEA for language is different from the EEA for mate preference which is different still from the EEA for hands. I suppose I could also mention that every evolutionary psychologists knows that people do some things today – like wear heels and use hormonal birth control – that they used to not do during our evolutionary history, but, at this point, it seems to be so blindingly obvious to anyone that it hardly seems worth repeating. Final round goes to stereotype confirmation.

“I don’t understand your position, yet remain convinced you’re wrong!”

Now I would love to be the good, progressive scientist that Kate wants me to be and disconfirm the stereotype that evolutionary psychology’s critics are ignorant of the field they’re criticizing, but it’s difficult to do so when she, like so many others, confirms that stereotype. Of the concerns she lists, a collective none of them deal with the theoretical foundations of the field, the first two have more to do with research methodology than evolutionary psychology specifically (and even those two don’t paint evolutionary psychologists in a particularly bad light), and the remaining ones get basic definitions wrong while simultaneously misrepresenting the researchers in the field as being unsophisticated. Now, in all fairness to Kate, she does mention that she’s talking about what she thinks bad evolutionary psychology is, but it’s not clear to me that she has a solid enough grasp of the field to be making those kinds of pronouncements in the first place (not to mention she waivers back and forth between using that qualifier and dropping it, writing about evolutionary psychology as a whole). I also really don’t appreciate her insinuation that our field does politically-motivated research with the intent of keeping LBGT folks second-class citizens at the end either (which, by the way, we don’t; Tybur, Miller, & Gangestad, 2007), but at least she’s upfront about her biases, no matter how incorrect they happen to be.

References: Tybur, J., Miller, G., & Gangestad, S. (2007). Testing the controversy: An empirical examination of adaptationists’ attitudes towards politics and science. Human Nature, 18 (4), 313-328 DOI: 10.1007/s12110-007-9024-y

Should You Give A Damn About Your Reputation (Part 2)

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In my last post, I outlined a number of theoretical problems that stand in the way of reputation being a substantial force for maintaining cooperation via indirect reciprocity. Just to recap them quickly: (1) reputational information is unlikely to be spread much via direct observation, (2) when it is spread, it’s most likely to flow towards people who already have a substantial amount of direct interactions with the bearer of the reputation, and (3) reputational information, whether observed visually or transmitted through language, might often be inaccurate (due to manipulation or misperception) or non-diagnostic of an individual’s future behavior, either in general or towards the observer. Now all of this is not to say that reputational information would be entirely useless in predicting the future behavior of others; just that it seems to be an unlikely force for sustaining cooperation in reality, despite what some philosophical intuitions written in the language of math might say. My goal today is to try and rescue reputation as a force to be reckoned with.

In all fairness, I did only say that I would try…

The first – and, I think, the most important – step is to fundamentally rethink what this reputational information is being used to assess. The most common current thinking about what third-party reputation information is being used to assess would seem to be the obvious: you want to know about the character of that third party, because that knowledge might predict how that third party will act towards you. On top of assuming away the above problems, then, one would also need to add in the assumption that interactions between you and the third party would be relatively probable. Let’s return to the example of your friend getting punched by a stranger at a bar one night. Assuming that you accurately observed all the relevant parts of the incident and the behavior of the stranger there was also predictive of how he would behave towards you (that is, he would attack you unprovoked), if you weren’t going to interact with that stranger anyway, regardless of whether you received that information or not, while that information might be true, it’s not valuable.

But what if part of what people are trying to assess isn’t how that third party will behave towards them, but rather how that third party will behave towards their social allies. To clarify this point, let’s take a simple example with three people: A, B, and X. Person A and B will represent you and your friend, respectively; person X will represent the third party. Now let’s say that A and B have a healthy, mutually-cooperative relationship. Both A and B benefit form this relationship and have extensive histories with each other. Person B and X also have a relationship and extensive histories with one another, but this one is not nearly as cooperative; in fact, person X is downright exploitative over B. Given that A and X are otherwise unlikely to ever interact with each other directly, why would A care about what X does?

The answer to this question – or at least part of that answer – involves A and X interacting indirectly. This requires the addition of a simple assumption, however: the benefits that person B delivers to person A are contingent on person B’s state. To make this a little less abstract, let’s just use money. Person B has $10 and can invest that money with A. For every dollar that B invests, both players end up making two. If B invests all his money, then, both him and person A end up with $20. In the next round, B has his $10, but before he gets a chance to invest it with A, person X comes along and robs B of half of it. Now, person B only has $5 left to invest with A, netting them both $10. In essence, person X has now become person A’s problem, even though the two never interacted. All this assumption does, then, is make clear the fact that people are interacting in a broader social context, rather than in a series of prisoner’s dilemmas where your payoff only depends on your own, personal interactions.

Now if only there was a good metaphor for that idea…

With the addition of this assumption, we’re able to circumvent many of the initial problems that reputational models faced. Taking them in reverse order, we are able to get around the direct-interaction issue, since your social payoffs now co-vary to some extent with your friends, making direct interaction no longer a necessary condition. It also allows us to circumvent the diagnosticity issue: there’s less of a concern about how a third party might interact with you differently than your friend because it’s the third party’s behavior towards your friend that you’re trying to alter. It also, to some extent, allows us to get around the accuracy issue: if your friend was attacked and lies to you about why they were attacked, it matter less, as one of your primary concerns is simply making sure that your friend isn’t hurt, regardless of whether your friend was in the right or not. This takes some of the sting out of the issues of misperception or misinformation.

That said, it does not take all the sting out. In the previous example, person A has a vested interest in making sure B is not exploited, which gives person B some leverage. Let’s alter the example a bit, and say that person B can only invest $5 with person A during any given round; in that case, if X steals $5 from B’s initial $10, it wouldn’t affect person A at all. Since person B would rather not be exploited, they might wish to enlist A’s help, but find person A less than eager to pitch in. This leaves person B with three options: first, B might just suck it up and suffer the exploitation. Alternative, B might consider withholding cooperation from A until A is willing to help out, similar to B going on a strike. If person B opts for this route, then all concerns for accuracy are gone; person A helping out is merely a precondition of maintaining B’s cooperation. This strategy is risky for B, however, as it might look like exploitation from A’s point of view. As this makes B a costlier interaction partner, person A might consider taking his business elsewhere, so to speak. This would leave B still exploited and out a cooperative partner.

There is another potential way around the issue, though: person B might attempt to persuade A that person X really was interfering in such a way that made B unable to invest; that is, person B might try to convince A that X had really stolen $8 instead of $5. If person B is successful in this task, it might still make him look like a costlier social investment, but not because he is himself attempting to exploit A. Person B looks like he really does want to cooperate, but is being prevented from doing so by another. In other words, B looks more like a true friend to A, rather than just a fair-weather one or an exploiter (Tooby & Cosmides, 1996). In this case, something like manifesting depression might work well for B to recruit support to deal with X (Hagen, 2003). Even if such behavior doesn’t directly stop X from interfering in B’s life, though, it might also prompt A to increase their investment in B to help maintain the relationship despite those losses. Either way, whether through avoiding costs or gaining benefits, B can leverage their value with A in these interactions and maintain their reputation as a cooperator.

“I’ll only show back up to work after you help me kill my cheating wife”

Finally, let’s step out of the simple interaction into the bigger picture. I also mentioned last time that, sometimes, cooperating with one individual necessitates defecting on another. If person A and B allied against person X, if person Y is cooperating with X, person Y may now also incur some of the punishment A and B direct at X, either directly or indirectly. Again, to make this less abstract, consider that you recently found out your friend holds a very unpopular social opinion (say, that women shouldn’t be allowed to vote) that you do not. Other people’s scorn for your friend now makes your association with him all the more harmful for you: by benefiting him, you can, by proxy, be seen to either be helping him promote his views, or be inferred to hold those same views yourself. In either case, being his friend has now become that much costlier, and the value of the relationship might need to be reassessed in that light, even if his views might otherwise have little impact on your relationship directly. Knowing that someone has a good or bad reputation more generally can be seen as useful information in this light, as it might tell you all sorts of things about how costly an association with them might eventually prove to be.

References: Hagen, E.H. (2003). The bargaining model of depression. In: Genetic and Cultural Evolution of Cooperation, P. Hammerstein (ed.). MIT Press, 95-123

Tooby, J., & Cosmides, L. (1996). Friendship and the banker’s paradox:Other pathways to the evolution of adaptations for altruism. Proceedings of the British Academy (88), 119-143

Should You Give A Damn About Your Reputation? (Part 1)

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According to Nowak (2012) and his endlessly-helpful mathematical models, once one assumes that cooperation can be sustained via one’s reputation, one ends up with the conclusion that cooperation can, indeed, be sustained (solely) by reputation, even if the same two individuals in a population never interact with each other more than once. As evidenced by the popular Joan Jett song, Bad Reputation, however, one can conclude there’s likely something profoundly incomplete about this picture: why would Joan give her reputation the finger in this now-famous rock anthem, and why would millions of fans be eagerly singing along, if reputation was that powerful of a force? The answer to this question will involve digging deeper into the assumptions that went into Nowak’s model and finding where they have gone wrong. In this case, not only are some of the assumptions of Nowak’s model a poor fit to reality in terms of the one’s he makes, but, perhaps more importantly, also poor in regards to what assumptions he doesn’t make.

Unfortunately, my reply to some current thinking about reputation can’t be expressed as succinctly.

The first thing worth pointing out here is probably that Joan Jett was wrong, even if she wasn’t lying: she most certainly did give a damn about her reputation. In fact, some part of her gave so much of a damn about her reputation that she ended up writing a song about it, despite that not being her conscious intent. More precisely, if she didn’t care about her reputation on any level, advertising that fact to others would be rather strange; it’s not as if that advertisement would provide Joan herself with any additional information. However, if that advertisement had an effect on the way that other people viewed her – updating her reputation among the listeners – her penning of the lyrics is immediately more understandable. She wants other people to think she doesn’t care about her (bad) reputation; she’s not trying to remind herself. There are a number of key insights that come from this understanding, many of which speak to the assumptions of these models of cooperation.

The initial point is that Joan needed to advertise her reputation. Reputations do not follow their owners around like a badge; they’re not the type of thing that can be accurately assessed on sight. Accordingly, if one does not have access to information about someone’s reputation, then their reputation, good or bad, would be entirely ineffective at deciding how to treat that someone. This problem is clearly not unsolvable, though. According to Sigmund (2012), the simple way around this problem involves direct observation: if I observe a person being mean to you, I can avoid that person without having to suffer the costs of their meanness firsthand. Simple enough, sure, but there are many problems with this suggestion too, some of which are more obvious than others. The first of these problems would be that a substantial amount – if not the vast majority – of (informative and relevant) human interactions are not visible to many people beyond those parties who are already directly involved. Affairs can be hidden, thieves can go undetected, and promises can be made in private, among other things (like, say, browsing histories being deleted…). Now that concern alone would not stop reputations derived from indirect information from being useful, but it would weaken its influence substantially if few people ever have access to it.

There’s a second, related concern that weakens it further, though: provided an interaction is observed by other parties, those who most likely to be doing the observing in the first place are the people who probably already have directly interacted with one or more of the others they’re observing; a natural result of people not spending their time around each other at random. People only have a limited amount of time to spend around others, and, since one can’t be in two places at once, you naturally end up spending a good deal of that time with friends (for a variety of good reasons that we need not get into now). So, if the people who can make the most use of reputational information (strangers) are the least likely to be observing anything that will tell them much about it, this would make indirect reciprocity a rather weak force. Indeed, as I’ve covered previously, research has found that people can make use of indirectly-acquired reputation information, and do make use of it when that’s all they have. Once they have information from direct interactions, however, the indirect variety of reputational information ceases to have an effect on their behavior. It’s your local (in the social sense; not necessarily physical-distance sense) reputation that’s most valuable. Your reputation more globally – among those you’re unlikely to ever interact much with – would be far less important.

See how you don’t care about anyone pictured here? The feeling’s mutual.

The problems don’t end there, though; not by a long shot. On top of information not being available, and not being important, there’s also the untouched matter concerning whether the information is even accurate. Potential inaccuracies can come in three forms: passive misunderstandings, active misinformation, and diagnosticity. Taking these in order, consider a case where you see your friend get punched in the nose from across the room by a stranger. From this information, you might decide that it’s best to steer clear of that stranger. This seems like a smart move, except for what you didn’t see: a moment prior your friend, being a bit drunk, had told the stranger’s wife to leave her husband at the bar and come home with him instead. So, what does this example show us? That even if you’ve directly observed an interaction, you probably didn’t observe one or more previous interactions that led up to the current one, and those might well have mattered. To put this in the language of game theorists, did you just witness a cooperator punishing a defector, a defector harming a cooperator, or some other combination? From your lone observation, there’s no sure way to tell.

But what if your friend told you that the other person had attacked them without provocation? Most reputational information would seem to spread this way, given that most human interaction is not observed by most other people. We could call this the “taking someone else’s word for it” model of reputation. The problems here should be clear to anyone who has ever had friends: it’s possible your friend had misinterpreted the situation, or that your friend had some ulterior motive for actively manipulating your perception that person’s reputation. To again rephrase this in terms of game theorist’s language, if cooperators can be manipulated into punishing other cooperators, either through misperception or misinformation, this throws another sizable wrench into the gears of the reputation model. If one’s reputation can be easily manipulated, this, to some extent, will make cooperation more costly (if one fails to reap some of cooperation’s benefits or can offset some of defection’s costs). Talk is cheap, and indirect reciprocity models seem to require a lot of it.

This brings us to the final accuracy point: diagnosticity. Let’s say that, hypothetically, the stranger did attack your friend without provocation, and this was observed accurately. What have you learned from this encounter? Perhaps you might infer that the stranger is likely to be an all-around nasty person, but there’s no way to tell precisely how predictive that incident is of the stranger’s later behavior, either towards your friend or towards you. Just because the stranger might make a bad social asset for someone else, it does not mean they’ll make a bad social asset for you, in much the same way that my not giving a homeless person change doesn’t mean my friends can’t count on my assistance when in need. Further, having a “bad” reputation among one group can even result in my having a good relationship with a different group; the enemy of my enemy is my friend, as the saying goes. In fact, that last point is probably what Joan Jett was advertising in her iconic song: not that she has a bad reputation with everyone, just that she has a bad reputation among those other people. The video for her song would lead us to believe those other people are also, more or less, without morals, only taking a liking to Joan when she has something to offer them.

The type of people who really don’t give a damn about their reputation.

While this in not an exhaustive list of ways in which many current assumptions of reputation models are lacking (there are, for instance, also cases where cooperating with one individual necessitates defecting on another), it still poses many severe problems that need to be overcome. Just to recap: information flow is limited, that flow is generally biased away from the people who need it the most, there’s no guarantee of the accuracy of that information if it’s received, and that information, even if received and accurate, is not necessarily predictive of future behavior. The information might not exist, might not be accurate, or might not matter. Despite these shortcomings, however, what other people think of you does seem to matter; it’s just that the reasons it matters need to be, in some respects, fundamentally rethought. Those reasons will be the subject of the next post.

References: Nowak, M. (2012). Evolving cooperation. Journal of Theoretical Biology, 299, 1-8.

Sigmund, K. (2012). Moral assessment in indirect reciprocity Journal of Theoretical Biology, 299, 25-30 DOI: 10.1016/j.jtbi.2011.03.024

5 Weak Ideas About The Origin Of Homosexuality: A Reply

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Back at the end of last month, Mark Van Vugt presented what he considered to be five candidate selection pressures which might explain how homosexuality as an orientation – the exlcusive preference for same-sex sexual partners – came to both (a) exist in human populations in the first place, and (b) have its existence was maintained in the face of, what appear to be, obvious reproductive disadvantages. In each of these five cases I find the arguments lacking for either theoretical or empirical reasons, and, in most cases, both. Before I get to the science, however, I would like to deal with a troubling claim that Mark makes at the beginning of his post:

“The converging findings suggest that exclusive homosexuality is not a “life style choice” but a perfectly natural sexual orientation….Although these findings make a reasonably strong claim that homosexuality is part of someone’s genotype, there is still much speculation as to how it got there.”

There are three problems I have with those two above statements (admittedly, juxtapositioned for effect) that are worth pointing out. The first is the language used: while I’m in no way about to tell you that being gay is a choice (I happen to think it isn’t one), I will point out that the opposite of “choice” is not “genetic” or “natural”. If it was discovered tomorrow that homosexuality was determined by some environmental variable, say, a specific pathogen affecting development, (Cochran, Ewald, & Cochran, 2000) that would make homosexuality no more or less of a “choice”. The second issue is that all biological traits are equally and entirely codetermined both by environmental and genetic factors. Accordingly, saying homosexuality (or any single other trait) is “part of someone’s genotype” is both trivially and true as well as potentially misleading for those who are not well-versed in genetics.

Finally, the third issue is a cautionary point I made about a year-and-a-half ago: presumably, all the talk about choice, genes, and “being natural” has little to do with statements of fact, but are rather about the moral status of homosexuality. While I fully support the moral acceptance of homosexuality, I would be very wary of basing that support on the notion that homosexuality is a “genetic” trait that people “don’t choose”. Not only do I think homosexuality should be accepted regardless of whether it’s a choice or caused by some environmental factor, but I further would hate to see the arguments for acceptance slip away on the basis of the concordance data not panning out (which we’ll see in a moment, it does not).

Politics and science make awkward bedfellows, not unlike gay men and women…

Now that the political-stuff is out of the way, we can start dealing with some of Mark’s claims. The first thing I’ll take issue with there is the prevalence data. The stable 8% figure that Mark mentions is one that exceeds most every published estimate of homosexuality I’ve seen; those have typically hovered about 1-3%. Bear in mind, one isn’t simply trying to estimate the percentage of people who have had a homosexual experience before; it’s preferences which are of primarily interest. Further, there is little reason to think that such a figure is stable, as Mark implies it is, across time, place, or history. It well might have been, but one would have an awful hard time demonstrating that it is if one wishes to go beyond pure assertion.

As for his next point, yes; there is indeed evidence that twins tend to share a sexual orientation, as they do many other things. However, the concordance rates for a homosexual orientation among identical twins (that is, given that one twin has a homosexual orientation, how often does their co-twin have a similar orientation)  is only about 30%, and about 8.3% for non-identical twin pairs (Kendler et al, 2000). To make matters even more complicated, it’s worth noting that these concordance rates only tells us that some amount of what these twins share – genes, prenatal, and postnatal environments – makes it more likely that both will eventually develop a homosexual orientation, but it doesn’t tell us what that something is. Twin pairs, for instance, are similarly concordant for patterns of infectious disease (Cochran, Ewald, & Cochran, 2000), but it doesn’t mean they inherent genes that function to make them sick.

Finally, before getting to the selection pressures, it’s also worth countering the claim that homosexuality is well-documented in non-human species. Sure, there are some species that will, occasionally, engage in brief interactions more typical of mixed-sex pairs, be those interactions sexual or non-sexual in nature. What needs to be explained when it comes to homosexuality is not homosexual behaviors, but rather heterosexual avoidance. This more-or-less exclusive sexual preference for same-sex conspecifics has only been documented in rams, to my knowledge, and in no other non-human species, much less many or most of them.

Selection Pressures: Kin Selection
The first of the five selection pressures that Mark mentions is kin selection: helping others who share your genes reproduce. As Mark correctly points out, there’s little evidence for his hypothesis being correct, but the issues are much larger than that. For starters, the relationship coefficients don’t work well here: for each offspring a homosexual individual doesn’t produce, they would need to ensure that a full sibling produced an additional two that they otherwise wouldn’t have had for them to just break even and for this hypothesis to work. This would require an intense level investment that, if it existed, would be plainly obvious to any observer. It’s not enough that a homosexual individual is occasionally or even often nice to their relatives; they would need to be utterly devoted around the clock.

More to the point, though, is the seemingly apparent point that having a same-sex sexual attraction does nothing to help you invest in kin. Sure, maybe an asexual preference would work, if you wanted to save the time otherwise spent pursuing sex; a facultative heterosexual preference would probably do just as well, if not better. A homosexual orientation, on the other hand, is a complete waste of time; it would be a pointless distraction from the investment issue. Unless seeking out same-sex sexual relations was somehow functional in terms of increasing investment (or a rather odd byproduct), this explanation makes little sense.

Ants are very helpful, yet not very gay…

Selection Pressures: Group Selection
Group selection – the idea that a trait can spread if it offers group-wide advantages despite being individually detrimental – is a conceptual nonstarter, running counter to everything we know about how evolution works. Since I’ve written about this matter before on several occasions, there’s little need to continue beating this theoretical horse which has been dead since the 1960s. As Mark, again, points out, he knows of no evidence in favor of this hypothesis either, so there’s little less to say about it, other than that it doesn’t sound like a very “big” idea.

Selection Pressures: Sexual Attraction
This one, I admit, is probably the strangest of the selection pressures Mark posits. The idea here seems to be that because women might find homosexual men sexually attractive, this could give homosexual men a reproductive advantage. Now, perhaps I’m misunderstanding the basic idea in some fundamental way, but if an individual with a homosexual preference is found to be attractive by opposite sex individuals, it would seem to not matter much, as it’s quite unlikely that the two will ever end up having sex at all, let alone frequently. Provided these increased opportunities for sexual encounters even exist(Mark says there’s no evidence available that they do), they wouldn’t seem to do much good if the urge to take them is all but absent.

In case the problems aren’t plainly apparent at this point, imagine a hypothetical species of bird, like a peacock. In this species, males grow elaborate ornaments that females find to be attractive, generally speaking. Growing these ornaments, however, carries a cost: it makes the males sterile. In this case, no matter how attractive a male is to the females, his genes will never be benefited because of it. Attractiveness only matters so much as it leads to reproduction. No reproduction, no selection.

Selection Pressures: Balanced Selection
This argument at least poits that homosexuality is reproductively detrimental. These detriments are made up elsewhere, though, in the form of benefits to other carries of the genes. In essence, this argument says homosexuality is a lot like sickle-cell: harmful in some cases, but beneficial in others. There’s nothing theoreticall wrong with this possibility, but there are some serious practical hurdles. Specifically, if homosexual orientations ensured that 1-8% of the population was, effectively, sterile, there would need to be tremendous compensating benefits. Sickle-cell, for instance, is only common in areas that have a ton of malaria – which can kill huge minorities of populations and leave even more severely harmed – and pretty much the only known byproduct of its kind with a fitness hit as great as homosexuality (Cochran, Ewald, & Cochran, 2000). It also doesn’t fit well with the concordance rate data. So, while this explanation is theoretically possible, it’s highly improbable. At the risk of sounding like a broken record, there’s also no known evidence for this being the case.

Selection Pressures: Sexually Antagonistic Selection
This brings us to the final selection pressure. Here, the idea is that a gene is detrimental when it’s inherited by one sex, but beneficial in the other. This is another theoretically plausible suggestions with some consistent evidence behind it (but the account isn’t anywhere near complete, and only considers male homosexuality). Unfortunately for this suggestion, like the above hypothesis, it also suffers from the concordance rate data. It would also require that females consistently more than make up for the detriment to the male offspring, reproductively. Remember, this isn’t just a matter of slight disadvantages; this is a matter of effective sterility. Further, such sexually antagonistic issues tend to be weeded out over time, as any new modifications that can avoid the costs associated with expression in males will be selected for. Even if this was a viable account, then, it would still be far from a complete one, as it would not be able to explain why some of the twin pairs turn out concordant, but most don’t, why these reproductive costs have yet to be eliminated, and it’s missing an account of female homosexuality.

“Would you care for a sixth cup of weak tea?”

Out of the five “big” ideas, then, four seem to be basically dead in the water and the fifth, while potentially plausible, is by no means conclusive or complete. In my experience, poor outcomes like these can be seen frequently when people attempt to use scientific research to justify some political or moral opinion: any available evidence that can be potentially interpreted in a favorable light is seized upon, no matter how weak or nonsensical the underlying connection between the two is. The goal, after all, doesn’t appear to be accuracy, but rather persuasion; to the extent that the former helps with the latter, all the better for the persuader, but their need not be any necessary connection between the two goals.

References: Cochran, G., Ewald, P., & Cochran, K. (2000). Infectious Causation of Disease: An Evolutionary Perspective. Perspectives in Biology and Medicine, 43 (3), 406-448 DOI: 10.1353/pbm.2000.0016

Iemmola F. & Ciana, A. (2009). New evidence of genetic factors influencing sexual orientation in men: Female fecundity increases in the maternal line. Archives of Sexual Behavior, 38, 393-399.

Kendler, K.S., Thornton, L.M., Gilman, S.E., & Kessler, R.C. (2000). Sexual orientation in a U.S. national sample of twins and nontwin sibling pairs. American Journal of Psychiatry, 157, 1843-1846

Why Does Stephen Hate Bob (More Than His Wife)?

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“If a wife left her husband with three kids and no job/ to run off to fuck in Hawaii with some doctor named Bob/ you could skin them and drain them of blood so they die…especially Bob. Then you would be justice guy”. – Stephen Lynch, “Superhero”

For those of you not in the know, Stephen Lynch is a popular comedic musician. In the song, “Superhero”, Stephen gives the above description of what he would do were he “Justice Guy”. As one can gather, in this story, Stephen’s wife has run off with another man, resulting in Mr. Lynch temporarily experiencing a Predator-like urge for revenge. The interesting thing about this particular song is the emphasis that Stephen puts on his urge to kill Bob. It’s interesting in that it doesn’t make much sense, morally speaking: it’s not as if Bob, a third party who was not involved in any kind of relationship with Stephen, had any formal obligation to respect the boundaries of Stephen’s relationship with his wife. Looking out for the relationship, it seems, ought to have been his wife’s job. She was the person who had the social obligation to Stephen that was violated, so it seems the one who Stephen ought to mad at (or, at least madder at) would be his wife. So why does Stephen wish to especially punish Bob?

“I swear I’ll get you Bob, even if it’s the last thing I do!”

There are two candidate explanations I’d like to consider today to help explain the urge for this kind of Bob-specific punishment: one is slightly more specific to the situation at hand and the other applies to punishment interactions more generally, so let’s start off with the more specific case. Stephen wants his wife to behave cooperatively in terms of their relationship, and she seems less than willing to do so herself; presumably, some mating mechanisms in her brain is suggesting that the payoffs would be better for her to ditch her jobless husband to run off with a wealthy, high-status doctor. In order to alter the cost/benefit ratio to certain actions, then, Stephen entertains the idea of enacting punishment. If Stephen’s punishment makes his wife’s infidelity costlier than remaining faithful, her behavior will likely adjust accordingly. While punishing his wife can potentially be an effective strategy for enforcing her cooperation, it’s also a risky venture for Stephen on two fronts: (1) too much punishing of his wife – in this case, murder, though it need not be that extreme – can be counterproductive to his goals, as it would render her less able to deliver the benefits she previously provided to the relationship; the punishment might also be counterproductive because (2) the punishment makes the relationship less valuable still to his wife as new costs mount, resulting in her urge to abandon the relationship altogether for a better deal elsewhere growing even stronger.

The punishing of potential third parties – in this case, Bob – does not hold these same costs, though. Provided Bob was a stranger, Stephen doesn’t suffer any loss of benefits, as benefits were never being provided by Bob in the first place. If Stephen and Bob were previously cooperating in some form the matter gets a bit more involved, but we won’t concern ourselves with that for now; we’ll just assume the benefits his wife could provide are more valuable than the ones Bob could. With regard to the second cost – the relationship becoming costlier for the person punishment is directed at – this is, in fact, not a cost when that punishment is directed at Bob, but rather the entire point. If the relationship is costlier for a third party to engage in, due to the prospect of a potentially-homicidal partner, that third party may well think twice before deciding whether to pursue the affair any further. Punishing Bob would seem to look like the better option, then. There’s just one major hitch: specifically, punishing is costly for Stephen, both in terms of time, energy, and risk, and he may well need to direct punishment towards far more targets if he’s attempting to prevent his wife from having sex with other people.

Punishing third parties versus punishing one’s partner can be thought of, by way of analogy, to treating the symptoms or the cause of a disease, respectively. Treating the symptoms (deterring other interested men), in this case, might be cheaper than treating the underlying cause on an individual basis, but you may also need to continuously treat the symptoms (if his wife is rather interested with the idea of having affairs more generally). Depending on the situation, then, it might be ultimately cheaper and more effective to treat either the cause or the symptoms of the problem. It’s probably safe to assume that the relative cost/benefit calculations being worked out cognitively might ultimately be represented to some degree in our desires: if some part of Stephen’s mind eventually comes to the conclusion, for whatever reasons, that punishing one or more third parties would be the cheaper of the two options, he might end up feeling especially interested in punishing Bob.

All things considered, I’d say Bob had a pretty good run…

There is another, unexamined, set of costs, though, which brings us to the more general account. Stephen is not deciding whether to punish his wife and/or Bob in a social vacuum: what other people think about his punishment decisions will, in turn, likely effect Stephen’s perceptions of their attractiveness as options. If people are relatively lined up behind Stephen’s eventual decision, punishment suddenly becomes far less costly for Stephen to implement; by contrast, if others feel Stephen has gone to far and they align against him, his punishment would now become costlier and less effective (DeScioli & Kurzban, 2012). This brings us to a question I’ve raised before: would Stephen’s punishing of Bob result in the same social costs as the same punishment directed towards his wife? Strictly on the grounds that Bob is a man and Stephen’s wife is a woman, the answer to that question would seem to be “no”.

A paper by Glaeser and Sacerdote (2003) examined whether victim characteristics (like age and gender) were predictive of sentencing lengths for various crimes. The authors examined a sample of 1,772 cases in which manslaughter or murder charges were brought and a sentence was delivered, either due to a plea bargain or a conviction. Some of the expected racial bias seemed to raise its head, in that when the victim in question was black, the person sentenced for the killing was given less time (17.6 years, on average), overall, than when the victim was white (19.8 years). As was also the case in my last discussion of this topic, when the victim was a woman, sentence lengths were substantially shorter than when the victim was a man (17.5 vs 22.4 years, respectively). The difference is even starker when you consider the interaction between the gender of the person doing and kill and the gender of the person who got killed: when the victim was a man, if the killer was also a man, he would get about 18 years, on average; if the killer was a woman, that number drops to 11.3. For comparison’s sake, when the victim was a woman and the killer a woman, she would get about 17.5 years; if the killer was a man, that average was 23.1 years.

Those numbers, however, refer to all types of killings, so the sample was further restricted to vehicular homicides (about 7% of all homicides); essentially cases of people being killed by drunk drivers. These cases in particular are interesting because the victims here are, more or less, random; they just happened to be in the wrong place at the wrong time, and were not being targeted. Since these killings are relatively random, so to speak, the characteristics of the victim should be irrelevant to sentencing length, but they again were not. In these cases, if the person driving the car and doing the killing was a woman, she could expect a sentence of about 3 years for killing a man and 4.5 for killing another woman. If you replace the driver with a male, those numbers rise to 4.7 and 10.4 years respectively. Killing a woman netted a higher sentence in general, no matter your gender, but being a man doing the killing put you in an especially bad situation.

“Oh, good; we only hit a man. I was worried for a second there.”

So where does all that leave Stephen? If other people are more likely to align against Stephen for punishing his wife, relative to his punishing Bob, that, to some extent, makes the appeal of threatening or harming Bob seem (proportionally) all the sweeter. This analysis is not specifically targeted at gender (or race, or age), but at social value more generally. When deciding who to align with in these kinds of moral contexts, we should expect people to do so, in part, by cognitively computing (though not necessarily consciously) where their social investments will be most likely to yield a good return. Of course, determining the social value of others is not always easy task, as the variables which determine it will vary both in content and degree across people and across time. The larger point is simply that one’s social value can be determined not only by what you think of them, but by what others think of them as well. So even though Stephen’s wife was the only person cheating, Bob gets to be the party more likely to targeted for punishment, in no small part because of his gender.

References: Descioli, P. & Kurzban, R. (2012). A solution to the mysteries of morality. Psychological Bulletin, 1-20.

Glaeser, E., & Sacerdote, B. (2003). Sentencing in Homicide Cases and the Role of Vengeance The Journal of Legal Studies, 32 (2), 363-382 DOI: 10.1086/374707

“Couldn’t-Even-Possibly-Be-So Stories”: Just-World Theory

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While I was reading over a recent paper by Callan et al (2012) about the effects that a victim’s age has on people’s moral judgments, I came across something that’s particularly – and disappointingly – rare in most of the psychological literature: the authors explicitly thinking about possible adaptive functions of our psychology. That is to say, the authors were considering what adaptive problem(s) some particular aspect of human psychology might be designed to solve. In that regard, I would praise the authors for giving these important matters some thought. Their major stumbling point, however, is that the theory the authors reference, just-world theory, suggests an implausible function; one that couldn’t even potentially be correct.

Just-world theory, as presented by Hafer (2000), is a very strange kind of theory. It begins with the premise that people have a need to believe in a just or fair world, so people think that others shouldn’t suffer or gain unless they did something to deserve it. More precisely, “good” people are supposed to be rewarded and “bad” people are supposed to be punished, or something like that, anyway. When innocent people suffer, then, this belief is supposedly “threatened”, so, in order to remove the threat and maintain their just-world belief, people derogate the victim. This makes the victim seem less innocent and more deserving of their suffering, so the world can again be viewed as just.

I’ll bet that guy made Santa’s “naughty” list.

Phrased in terms of adaptationist reasoning, just-world theory would go something like this: humans face the adaptive problem of maintaining a belief in a just world in the face of contradictory evidence. People solve this problem with cognitive mechanisms that function to alter that contradictory evidence into confirmatory evidence. The several problems with this suggestion ought to jump out clearly at this point, but let’s take them one at a time and examine them in some more depth. The first issue is that the adaptive problem being posited here isn’t one; indeed, it couldn’t be. Holding a belief, regardless of whether that belief is true or not, is a lot like “feeling good”, in that neither of them, on their own, actually do anything evolutionary useful. Sure, beliefs (such as “Jon is going to attack me”) might motivate you to execute certain behaviors (running away from Jon), but it is those behaviors which are potentially useful; not the beliefs per se. Natural selection can only “see” what you do; not what you believe or how you feel. Accordingly, an adaptive problem could not even potentially be the maintaining of a belief.

But let’s assume for the moment that maintaining a belief could be a possible adaptive problem. Even granting this, just-world theory runs directly into a second issue: why would contradictory evidence “threaten” that belief in the first place? It seem perfectly plausible that an individual could simply believe whatever it is was important to believe and be done with it, rather than trying to rationalize that belief to ensure it’s consistent with other beliefs or accurate. For instance, say, for whatever reason, it’s adaptively important for people to believe that anyone who leaves their house at night will die. Then someone who believes this observes their friend Max leaving the house at night and return very much alive. The observer in this case could, it seems, go right along believing that anyone who leaves their house at night will die without also needing to believe either that (a) Max didn’t leave his house at night or (b) Max isn’t alive. While the observer might also believe one or both of those things, it would seem to be irrelevant as to whether or not they did.

On a related note, it’s also worth noting that just-world theory seems to imply that the adaptive goal here is to hold an incorrect belief – that “the world” is just. Now there’s nothing implausible about the suggestion that an organism can be designed to be strategically wrong in certain contexts; when it comes to persuading others, for instance, being wrong can be an asset at times. When you aren’t trying to persuade others of something, however, being wrong will, at best, be neutral to, at worst, exceedingly maladaptive. So what does Hafer (2000) suggest the function of such incorrect beliefs might be?

By [dissociating from an innocent victim], observers can at least be comforted that although some people are unjustly victimized in life, all is right with their own world and their own investments in the future (emphasis mine)

As I mentioned before, this explanation couldn’t even possibly work, as “feeling good” isn’t one of those things that does anything useful by itself. As such, maintaining an incorrect belief for the purposes of feeling good fails profoundly as a proper explanation for any behavior.

Not only is the world not just, it isn’t tuned into your thought frequencies either, no matter how strongly you incorrectly believe it is.

On top of all the aforementioned problems, there’s also a major experimental problem: the just-world theory only seems to have been tested in one direction. Without getting too much into the methodological details of her studies, Hafer (2000) found that when a victim was “innocent”, subjects who were primed for thinking about their long-term plans were slightly more likely to blame the victim for their negative life outcome, derogate them, and disassociate from them (i.e. they should have been more cautious and what happened to them is not likely to happen to me), relative to subjects who were not primed for the long term. Hafer’s interpretation of these results was that, at least in the long-term condition, the innocent victim threatened the just-world belief, so people in turn perceived the victim as less innocent.

While the innocent-victims-being-blamed angle was examined, Hafer (2000) did not examine the opposite context: that of the undeserving recipient. Let’s say there was someone you really didn’t like, and you found out that this someone recently came into a large sum of money through an inheritance. Presumably, this state of affairs would also “threaten” your just-world belief; after all, bad people are supposed to suffer, not benefit, so you’d be left with a belief-threatening inconsistency. If we presented subjects with a similar scenario, would we expect them to “protect” their just-world belief by reframing their disliked recipient as a likable and deserving one? While I admittedly have no data bearing on that point, my intuitive answer to the question would be a resounding “probably not”; they’d probably just view their rival as richer pain-in-their-ass after receiving the cash. It’s not as if intuitions about who’s innocent and guilty seem to shift simply on the basis of received benefits and harms; the picture is substantially more nuanced.

“If he was such a bad guy, why was he pepper-spraying people instead of getting sprayed?”

To reiterate, I’m happy to see psychologists thinking about functions when developing their research; while such a focus is by no means sufficient for generating good research or sensibly interpreting results (as we’ve just seen), I think it’s an important step in the right direction. The next major step would be for psychological researchers to better learn how to differentiate plausible and non-plausible functions, and for that they need evolutionary theory. Without evolutionary theory, ostensible explanations like “feeling good” and “protecting beliefs” can be viewed as acceptable and, in some cases, even as useful, despite them being anything but.

References: Callan, M., Dawtry, R., & Olson, J. (2012). Justice motive effects in ageism: The effects of a victim’s age on observer perceptions of injustice and punishment judgments Journal of Experimental Social Psychology, 48 (6), 1343-1349 DOI: 10.1016/j.jesp.2012.07.003

Hafer, C. (2000). Investment in Long-Term Goals andCommitment to Just Means Drive
the Need to Believe in a Just World Personality and Social Psychology Bulletin, 26, 1059-1073

The Tension Between Theory And Reality

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“In theory, theory and practice are the same. In practice, they are not.”

There is a relatively famous quote attributed to Michelangelo who was discussing his process of carving a statue: “I saw the angel in the marble and carved until I set him free”. Martin Nowak, in his book SuperCooperators (2011), uses that quote to talk about his admiration for using mathematical models to study cooperation. By stripping away the “noise” in the world, one can end up with some interesting conclusions. For instance, it was through this stripping away of the noise that led to the now-famous programming competition that showed us how successful a tit-for-tat strategy can be. There’s just one hitch, and it’s expressed in another relatively famous quote attributed to Einstein: “Whether you can observe a thing or not depends on the theory which you use. It is the theory which decides what can be observed.” Imagine instead that Michelangelo had not seen an angel in the marble, but rather a snake: he would have “released” the snake from the marble instead. That Michelangelo “saw” the angel in the first place seemed to preclude his seeing the snake – or any number of other possible images – that might have potentially been representable by the marble as well. I should probably also add that neither the snake nor the angel were actually “in” the marble in the first place…

“You see a medium for high art; I see new kitchen countertops”

The reason I bring up Nowak’s use of the Michelangelo quote is that both in his book and a recent paper (Nowak, 2012), Nowak stresses the importance of both (a) using mathematical models to reveal underlying truths by stripping away noise from the world, and (b) advocates for the readdition of that noise, or at least some of it, to make the models better at predicting real-world outcomes. The necessity of this latter point is demonstrated neatly by the finding that, as the rules of the models designed to assess cooperation shifted slightly, the tit-for-tat strategy no longer emerged as victorious. When new variables – ones previously treated as noise – are introduced to these games, new strategies can best tit-for-tat handily. Sometimes the dominant strategy won’t even remain static over time, shifting between patterns of near universal cooperation, universal defection, and almost anything in between. That new pattern of results doesn’t mean that a tit-for-tat strategy isn’t useful on some level; just that it’s usefulness is restricted to certain contexts, and those contexts may or may not be represented in any specific model.

Like Michelangelo, then, these theoretical models can “see” any number of outcomes (as determined by the initial state of the program and its governing rules); like Einstein, these models can also only “see” what they are programmed to see. Herein lies the tension: these models could be excellent for demonstrating the many things (like group selection works), but many of many those things which can be demonstrated in the theoretical realm are not applicable to the reality that we happen to live in (also like group selection). The extent to which those demonstrations are applicable to the real world relies on the extent to which the modeller happened to get things right. For example, let’s say we actually had a slab of marble with something inside it and it’s our goal to figure out what that something is: a metaphorical description of doing science. Did Michelangelo demonstrate that this something was the specific angel he had in mind by removing everything that wasn’t that angel from an entirely different slab of marble?  Not very convincingly; no. He might have been correct, but there’s no way to tell without actually examining the slab with that something inside of it directly. Because of this, mathematical models do not serve as a replacement for experimentation or theory in any sense.

On top of that concern, a further problem is that, in the realm of the theoretical, any abstract concept (like “the group”) can be granted as much substance as any other, regardless of whether those concepts can be said to exist in reality; one has a fresh slab of marble that they can “see” anything in, constrained only by their imagination and programming skills. I could, with the proper technical know-how, create a mathematical model that demonstrates that people with ESP have a fitness advantage over those without this ability. By contrast, I could create a similar model that demonstrates that people without ESP have a fitness advantage over those with the ability. Which outcome will eventually obtain depends entirely on the ways in which I game my model in favor of one conclusion or the other. Placed in that light, (“we defined some strategy as working and concluded that it worked”) the results of mathematical modeling seem profoundly less impressive. More to the point, however, the outcome of my model says nothing about whether or not people actually have these theoretical ESP abilities in the first place. If they don’t, all the creative math and programming in the world wouldn’t change that fact.

Because, eventually, Keanu Reeves will stop you.

As you can no doubt guess by this point, I don’t hold mathematical modeling in the same high esteem that Nowak seems to. While its theoretical utility is boundless, its practical utility seems extremely limited, relying on the extent to which the assumptions of the programmer approach reality. With that in mind, I’d like to suggest a few other details that have not yet seemed to have been included in these models of cooperation. That’s not to say that the inclusion of these variables would allow a model to derive some new and profound truths – as these models can only see what they are told to see and how they are told to see it – just that these variables might help, to whatever degree, the models better reflect reality.

The first of these issues is that these cooperation games seem to be played using an identical dilemma between rounds; that is to say there’s only one game in town, and the payoff matrices for cooperation and defection remain static. This, of course, is not the way reality works: cooperation is sometimes mutually beneficial, other times mutually detrimental, and still others only beneficial for one of the parties involved, and all that changes the game substantially. Yes, this means we aren’t strictly dealing with cooperative dilemmas anymore, but reality is not made up of strictly cooperative dilemmas, and that matters if we’re trying to draw conclusions about reality. Adding this consideration into the models would mean that behavioral strategies are unlikely to ever cycle between  “always cooperate” or “always defect” as Nowak (2012) found that they did in his models. Such strategies are too simple-minded and underspecified to be practically useful.

A second issue involves the relative costs and benefits to cooperation and defection even within the same game. Sometimes defecting may lead to great benefits for the defector; at others, defecting may only lead to small benefits. A similar situation holds for how much of a benefit cooperation will bring to one’s partner. A tit-for-tat strategy could be fooled, so to speak, by this change of rules (i.e. I could defect on you when the benefits for me are great and reestablish cooperation only when the costs to cooperation are low). As cooperation will not yield identical payoffs over time more generally, cooperation will also not yield identical payoffs between specific individuals. This would make some people more valuable to have as a cooperative partner than others and, given that cooperation takes some amount of limited time and energy, this means competition for those valuable partners. Similarly, this competition can also mean that cooperating with one person entails simultaneously defecting against another (cooperation here is zero-sum; there’s only so much to go around). Competition for these more valuable individuals can lead to all sorts of interesting outcomes: people being willing to suffer defection for the privilege of certain other associations; people actively defecting on or punishing others to prevent those others from gaining said associations; people avoiding even trying to compete for these high value players, as their odds of achieving such associations are vanishingly low. Basically, all sorts of politically-wise behaviors we see from the characters in Game in Thrones that don’t find themselves represented in these mathematical models yet.

We might also want to add a stipulations for in-game beheadings.

A final issue is that information that individuals in these games are exposed to: it’s all true information. In the non-theoretical realm, it’s not always clear as to whether someone you’ve been interacting with cooperated or defected, or the degree of effort they put into the venture even if they were on the cooperating side of the equation. If individuals in these games could reap the benefits of defecting while simultaneously convincing others that they had cooperated, that’s another game-changer. Modeling all of this is, no doubt, a lot of work, but potentially doable. It would lead to all sorts of new set of findings about which strategies worked and which one didn’t, and how, and when, and why. The larger point, however, is that the results of these mathematical models aren’t exactly findings; they’re restatements of our initial intuitions in mathematical form. Whether those intuitions are poorly developed and vastly simplified or thoroughly developed and conceptually rich is an entirely separate matter, as they’re all precisely as “real” in the theoretical domain.

References: Nowak, M. (2011). SuperCooperators: Altruism, evolution, and why we need each other to succeed. New York: Free Press

Nowak, M. (2012). Evolving cooperation Journal of Theoretical Biology, 299, 1-8 DOI: 10.1016/j.jtbi.2012.01.014

The Fight Over Mankind’s Essence

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All traits of biological organisms require some combination and interaction of genetic and non-genetic factors to develop. As Tooby and Cosmides put it in their primer:

Evolutionary psychology is not just another swing of the nature/nurture pendulum. A defining characteristic of the field is the explicit rejection of the usual nature/nurture dichotomies — instinct vs. reasoning, innate vs. learned, biological vs. cultural. What effect the environment will have on an organism depends critically on the details of its evolved cognitive architecture.

The details of that cognitive architecture are, to some extent, what people seem to be referring to when they use the word “innate”, and figuring out the details of that architecture is a monumental task indeed. For some reason, this task of figuring out what’s “innate” also draws some degree of what I feel is unwarranted hostility and precisely why it does is a matter of great interest. One might posit that some of this hostility is due to the term itself. “Innate” seems to be a terribly problematic term for the same two reasons that most other contentious terms are: people can’t seem to agree on a clear definition for the word or a  context to apply it in, but they still use it fairly often despite that. Because of this, interpersonal communication can get rather messy, much like two teams trying to play a sport in which each is playing the game under a different set of rules; a philosophical game of Calvinball. I’m most certainly not going to be able to step into this debate and provide the definition for “innate” that all parties will come to intuitively agree upon and use consistently in the future. Instead, my goal is to review two recent papers that examined the contexts in which people’s views of innateness vary.

“Just add environment!” (Warning: chicken outcome will vary with environment)

Anyone with a passing familiarity in the debates that tend to surround evolutionary psychology will likely have noticed that most of these debates tend to revolve around issues of sex differences. Further, this pattern tends to hold whether it’s a particular study being criticized or the field more generally; research on sex differences just seems to catch a disproportionate amount of the criticism, relative to most other topics, and that criticism can often get leveled at the entire field by association (even if the research is not published in an evolutionary psychology, and even if the research is not conducted by people using an evolutionary framework). While this particular observation of mine is only an anecdote, it seems that I’m not alone in noticing it. The first of the two studies on attitudes towards innateness was conducted by Geher & Gambacorta (2010) on just this topic. They sought to determine the extent to which attitudes about sex differences might be driving opposition to evolutionary psychology and, more specifically, the degree to which those attitudes might be correlated with being an academic, being a parent, or being politically liberal.

Towards examining this issue, Geher & Gambacorta (2010) created questions aimed at assessing people attitudes in five domains: (1) human sex differences in adulthood, (2) human sex differences in childhood, (3) behavioral sex differences in chickens, (4) non-sex related human universals, and (5) behavioral differences between dogs and cats. Specifically, the authors asked about the extent to which these differences were due to nature or nurture. As mentioned in the introduction, this nature/nurture dichotomy is explicitly rejected in the conceptual foundations of evolutionary psychology and is similarly rejected by the authors as being useful. This dimension was merely used in order to capture the more common attitudes about the nature of biological and environmental causation, where the two are often seen as fighting for explanatory power in some zero-sum struggle.

Of the roughly 270 subjects who began the survey, not all of them completed every section. Nevertheless, the initial sample included 111 parents and 160 non-parents, 89 people in academic careers and 182 non-academics, and the entire sample was roughly 40 years old and mildly politically liberal, on average. The study found that political orientation was correlated with judgments of whether sex differences in humans (children and adults) were due to nature or environment, but not the other three domains (cats/dogs, chickens/hens, or human universals): specifically, those with more politically liberal leanings were also more likely to endorse environmental explanations for human sex differences. Across other domains there were some relatively small and somewhat inconsistent effects, so I wouldn’t make much of them just yet (though I will mention that women’s studies and sociology fields seemed consistently more inclined to chalk each domain – excepting the differences between cats and dogs – up to nurture, relative to other fields; I’ll also mention their sample was small). There was, however, a clear effect that was not discussed in the paper:subjects were more likely to chalk non-human animal behavior up to nature, relative to human behavior, and this effect seemed more pronounced with regards to sex differences specifically. With these findings in mind, I would echo the conclusion of the paper that there is appears to be some political, or, more specifically, moral dimension to these judgments of the relative roles of nature and nurture. As animal behavior tends to fall outside of the traditional human moral domain, chalking their behavior up to nature seemed less unpalatable for the subjects.

See? Men and women can both do the same thing on the skin of a lesser beast.

The next paper is a new release from Knobe & Samuels (2013). You might remember Knobe from his other work in asking people slightly different questions and getting vastly different responses, and it’s good to see he’s continuing on with that proud tradition. Knobe & Samuels begins by asking the reader to imagine how they’d react to the following hypothetical proposition:

Suppose that a scientist announced: ‘I have a new theory about the nature of intention. According to this theory, the only way to know whether someone intended to bring about a particular effect is to decide whether this effect truly is morally good or morally bad.’

The authors predict that most people would reject this piece of folk psychology made explicit; value judgments are supposed to be a different matter entirely from tasks like assessing intentionality or innateness, yet these judgments do not appear to be truly be independent from each other in practice. Morally negative outcomes are rated as being more intentional than morally positive ones, even if both are brought about as a byproduct of another goal. Knobe & Samuels (2013) sought to extent this line of research in the realm of attitudes about innateness.

In their first experiment, Knobe & Samuels asked subjects to consider an infant born with a rare genetic condition. This condition ensures that if a baby breastfeeds in the first two weeks of life it will either have extraordinarily good math abilities (condition one) or exceedingly poor math skills (condition two). While the parents could opt to give the infant baby formula that would ensure the baby would just turn out normal with regard to its math abilities, in all cases the parents were said to have opted to breastfeed, and the child developed accordingly. When asked about how “innate” the child’s subsequent math ability was, subjects seemed to feel that baby’s abilities were more innate (4.7 out of 7) when they were good, relative to when those abilities were poor (3.4). In both cases, the trait depended on the interaction of genes and environment and for the same reason, yet when the outcome was negative, this was seen as being less of an innate characteristic. This was followed up by a second experiment where a new group of subjects were presented with a vignette describing a fake finding about human’s genes: if people experienced decent treatment (condition one) or poor treatment (condition two) by parents at least sometimes, then a trait would reliability develop. Since most all people do experience decent or poor treatment by their parents on at least some occasions, just about everyone in the population comes to develop this trait. When asked about how innate this trait was, again, the means through which it developed mattered: traits resulting from decent treatment were rated as more innate (4.6) than traits resulting from poor treatment (2.7).

Skipping two other experiments in the paper, the final study presented these cases either individually, with each participant seeing only one vignette as before, or jointly, with some subjects seeing both versions of the questions (good/poor math abilities, decent/poor treatment) one immediately after the other, with the relevant differences highlighted. When subjects saw the conditions independently, the previous effects were pretty much replicated, if a bit weakened. However, even seeing these cases side-by-side did not completely eliminate the effect of morality on innateness judgments: when the breastfeeding resulted in worse math abilities this was still seen as being less innate (4.3) than the better math abilities (4.6) and, similarly, when poor treatment led to a trait developing it was viewed as less innate (3.8) than when it resulted from better treatment (3.9). Now these differences only reached significance because of the large sample size in the final study as they were very, very small, so I again wouldn’t make much of them, but I do still find it somewhat surprising that there were still small differences to be talked about at all.

Remember: if you’re talking small effects, you’re talking psychology.

While these papers are by no means the last word on the subject, they represent an important first step in understanding the way that scientists and laypeople alike represent claims about human nature. Extrapolating these results a bit, it would seem that strong opinions about research in evolutionary psychology are held, at least to some extent, for reasons that have little to do with the field per se. This isn’t terribly surprising, as it’s been frequently noted that many critics of evolutionary psychology have a difficult time correctly articulating the theoretical commitments of the field. Both studies do seem to suggest that moral concerns play some role in the debate, but precisely why the moral dimension seems to find itself represented in the debate over innateness is certainly an interesting matter that neither paper really gets into. My guess is that it has something to do with the perception that innate behaviors are less morally condemnable than non-innate ones (hinting at an argumentative function), but that really just pushes the question back a step without answering it. I look forward to future research on this topic – and research on explanations, more generally – to help fill in the gaps of our understanding of this rather strange phenomenon.

References: Geher, G., & Gambacorta, D. (2010). Evolution is Not Relevant to Sex Differences in Humans Because I Want it That Way! Evidence for the Politicization of Human Evolutionary Psychology EvoS: The Journal of the Evolutionary Studies Consortium , 2, 32-47

Knobe, J., & Samuels, R. (2013). Thinking like a scientist: Innateness as a case study Cognition, 126 (1), 72-86 DOI: 10.1016/j.cognition.2012.09.003

Is The Exotic Erotic? Probably Not…

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Last time I wrote about the likely determinants of homosexuality, I ended up favoring the pathogen hypothesis that was put forth by Cochran, Ewald, and Cochran (2000) as the theory that had the most currently going for it. What is particularly interesting about my conclusion is how much empirical evidence directly confirms the theory: none. Don’t get me wrong; the pathogen hypothesis is certainly consistent with the known findings about homosexuality – such as the widely-varying reported concordance rates and the large fitness costs associated with the orientation – but being consistent with certain findings is not the same as being demonstrated by that evidence. If the currently most plausible theory for explaining homosexuality has, in essence, no direct evidence in its favor, that clearly must not be saying a lot about the alternative prospects. The two theories I covered last time – kin selection and sexually antagonistic selection – can’t even seem to account well for the existing evidence, so a neutral point with regard to the evidence is actually preferable. There was one theory that I neglected to mention last time, however, and this is a theory that purports to be able to explain both how heterosexual and homosexual orientations come to develop, and in both sexes, no less. If such a theory proved to have anything to it, then, it would be a highly valuable perspective indeed, so it deserves careful inspection.

“Nope; still not finding any indication of plausibility yet. Get the bigger microscope”

The theory, known as “Exotic Becomes Erotic” (EBE) was proposed by Daryl Bem (1996). If that name sounds familiar, it’s because this is the same Daryl Bem who also thought he found evidence for “extra-sensory porn-ception” in 2011, so we’re already not off to a good start. Pressing ahead despite that association, EBE puts the causal emphasis of developing a preferential attraction towards one sex or another on an individual’s perceptions of feeling different from other members of one sex: for instance, if a boy happens to not like sports, he will feel different from the majority of the other boys who do seem to like sports; if he does like sports, he’d feel different from the girls who did not. Following this perception of one sex as exotic, EBE posits that individuals will come to experience “non-specific, autonomic arousal” to the exotic group in question and, subsequently, that arousal will be transformed into an erotic preference for members of the initially exotic group. So, if you feel different from the boys or the girls, regardless of whether you’re a boy or a girl, you’ll come to be vaguely aroused by that sex – either by apprehension, anger, fear, curiosity, or really anything works, so long as it’s physiologically arousing – and then your body will, at some point, automatically turn that arousal into lasting sexual preferences.

Like most of the theories regarding homosexuality I discussed previously, this one also have very little actual evidence to support it. What it does have is a correlation between retrospective reports of childhood gender nonconformity and current sexual orientation. In fact, that single, underwhelming correlation is about all that EBE has going for it; everything else in the model is an assumption that’s largely built off that correlation. While a retrospective correlation is slightly better than having no evidence at all, it’s not better by a whole lot (in much the same way that 53% accuracy at guessing where some stimuli will show up between two options isn’t much better than 50%, yet apparently both are publishable). So, now that we’ve covered what the theory has going for it, let’s consider some of the things that EBE does not have going for it. You might want to take a break now to use the bathroom or get a snack, because this is a long list.

Let’s begin with the matter of this “non-specific physiological arousal”: at a bare minimum, EBE would require that the sex an individual perceived to be the least exotic ought to be consistently less physiologically arousing, on average, than the gender that individual did identify with. Without that arousal, there would be nothing to eventually convert into later sexual preference. So what does Bem have to say about the presence or absence of this arousal?

“To my knowledge, there is no direct evidence for the first step in this sequence beyond the well-documented observation that novel (“exotic”) stimuli produce heightened physiological arousal in many species, including our own”

So, in other words, there is no empirical evidence for this suggestion whatsoever. The problems, however, do not stop there: EBE is also massively under-specified in regards to how this hypothetical “non-specific arousal” is turned into eroticism in some cases but not others. While Bem (1996) proposes three possible mechanisms through which that transition might take place – sexual imprinting, the opponent process, and the extrinsic arousal effect – there are clearly non-human stimuli that produce a great deal of arousal (such as spiders, luxury cars, or, if we are talking about children, new toys) that does not get translated into later sexual attraction. Further, there are also many contexts in which gender-conforming children of the same sex will be around other while highly physiologically aroused (such as when boys are playing sports and competing against a rival team), but EBE would seem to posit that these high-aroused children would not develop any short- or long-term eroticism towards each other.

Nope; nothing even potentially erotic about that…

Bem might object that this kind of physiological arousal is somehow different, or missing a key variable. Perhaps, he might say, that in addition to this yet-to-be-demonstrated arousal, one also needs to feel different from the target of that arousal. Without being both exotic and arousing, there will be no lasting sexual preference developed. While such a clarification might seem to rescue EBE conceptually in this regard, the theory again falters by being massively under-specified. As Bem (1996) writes:

“…[T]he assertion that exotic becomes erotic should be amended to exotic – but not too exotic – becomes erotic. Thus, an erotic or romantic preference for partners of a different sex, race, or ethnicity is relatively common, but a preference for lying with the beasts in the field is not.”

In addition to not figuring out whether the arousal required for the model to work is even present, in no treatment of the subject does Bem specify precisely how much arousal and/or exoticism ought to be required for eroticism to develop, or how these two variables might interact in ways that are either beneficial or detrimental to that process. While animals might be both “exotic” and “highly arousing” to children, very rarely does a persistent sexual preference towards them develop; the same can be said for feelings between rival groups of boys, though in this case the arousal is generated by fear or anger. EBE does not deal with this issue so much as it avoids it through definitional obscurity.

Continuing along this thread of under-specificity, the only definition of “exotic” that Bem offers involves a perception of being different. Unfortunately for EBE, there are a near incalculable number of potential ways that children might feel different from each other, and almost none of those potential representations are predicted to result in later eroticism. While Bem (1996) does note that feeling different about certain things – interest in sports seems to be important here – appears to be important for predicting later homosexual orientation, he does not attempt to explain why feeling different about gender-related variables ought to be the determining factor, relative to non-gender related variables (such as intelligence, social status, or hair color). While erotic feelings do typically develop along gendered lines, EBE gives no a priori reason for why this should be expected. One could imagine a hypothetical population of people who develop preferential sexual attractions to other individuals across any number of non-gendered grounds, and EBE would have little to say about why this outcome does not obtain in any known human population.

The problem with this loose definition of exotic does not even end there. According to the data presented by Bem, many men and women who later reported a homosexual attraction also reported having enjoyed gender-typical activities (37 and 37%, respectively), having been averse to gender-atypical activities (52 and 19%), and having most of their childhood friends be of their same sex (58 and 40%). While these percentages are clearly different between homosexual and heterosexual respondents – with homosexuals reporting enjoying typical activities less, atypical ones more, and being more likely to predominately have friends of the opposite sex – EBE would seem to be at loss when attempting to explain why roughly half of homosexual men and women do not seem to report differing from their heterosexual counterparts in these important regards. If many homosexuals apparently did not view their own sex to be particularly exotic during childhood, there could be no hypothetical arousal and, accordingly, no eroticism. This is, of course, provided these retrospective accounts are even accurate in the first place and do not retroactively inflate the perceptions of feeling different to accord with their current sexual orientation.

“In light of not being hired, I can now officially say I never wanted your stupid job”

On a conceptual level, however, EBE runs into an even more serious concern. Though Bem (1996) is less than explicit about this, it would seem his model suggests that homosexuality is a byproduct of an otherwise adaptive system designed for developing heterosexual mate preferences. While Bem (1996) is likely correct in suggesting that homosexuality is not adaptive itself, his postulated mechanism for developing mate preference would likely have been far too detrimental to have been selected for. Bem’s model would imply that the mechanism responsible for generating sexual attraction, when functioning properly, functions so poorly that it would, essentially, render a rather large minority of the population effectively sterile. This would generate an intense selection pressure either towards any modification of the mechanism that did not preclude its transfer from one generation to the next or decisive selection towards a much greater gender conformity. Neither outcome seems to have obtained, which poses a new set of questions regarding why.

Precisely how such a poorly-functioning mechanism would have even come to exist in human populations in the first place is a matter that Bem never addresses. A major issue with the EBE perspective, then, is that it more-or-less takes for granted the base rate existence of homosexuality in human populations without asking why it ought to be that prevalent for humans but almost no other known species. Though Bem does not discuss it, almost every other species appears to navigate the process of developing sexual attraction in ways that do not result in large numbers of males or females developing exclusive same-sex attractions. If this was any other key adaptation, such a vision, and significant minorities of the population consistently went blind at very young ages in a world where being able to see is adaptive, we would want a better explanation for that failure than the kind that EBE can provide. Now if only the creator of EBE has some kind of ability to see into the future – an extra-sensory ability, if you will – to help him predict that his theory would run into these problems, they might have been avoided or dealt with…

References:Bem, D. (1996). Exotic becomes erotic: A developmental theory of sexual orientation. Psychological Review, 103 (2), 320-335 DOI: 10.1037//0033-295X.103.2.320

Cochran, G., Ewald, P., & Cochran, K. (2000). Infectious Causation of Disease: An Evolutionary Perspective Perspectives in Biology and Medicine, 43 (3), 406-448 DOI: 10.1353/pbm.2000.0016