Evolution, genetics & behavior

Two posts for your consideration.

On the Less Wrong weblog, Babies and Bunnies: A Caution About Evo-Psych. I am not one to make blanket dismissals of "evolutionary psychology." But, there are structural problems with the strong incentives toward generating hypotheses at the equipoise of novelty and intuitive plausibility. In other words, much of the evo-psych which penetrates the broader public mindspace is driven by demand-side forces.

Over at EconLog Bryan Caplan has a post, Born Gay, where the newly famous Ryan Sorba is shown to be pretty close to a total behavior genetics denialist. Until they find the "gay gene" Sorba & company will reject the behavior genetics findings. Unfortunately, if the "gay gene" hasn't been found yet, we might have to a wait a while (i.e., probably not a common variant of large effect). It would be nice to do a survey of the rejection of specific behavior genetic results as a function of ideological differences. The is-ought problem doesn't seem to be a problem for most people; it seems a background assumption, so that what is is actually back-derived from what ought to be.

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I think that for any behavioral-genetics claim that has important political or other consequences, the burden of proof must be strongly on those making the claim. The status quo (which is that we don't know for sure) quite properly has the benefit of the doubt. It's more or less on the "innocent until proven guilty" basis.

This just means that, for scientific claims that have extra-scientific consequences, there's an additional threshold of validation that must be crossed, besides the threshold internal to science which applies to all scientific claims. This is completely legitimate, because you're really dealing with two different questions in two different fields.

Even within the sciences, there's often resistance to discoveries of one science when its results are applied in a different science. (For example, I don't think that the consequences of Poincare's thee-body problem have been fully accepted by everyone yet.) This is normal scientific skepticism or conservativism.

If ev-psych and behavioral genetics people only introduced politically neutral results, there'd be less resistance, but that's really impossible given the nature of the fields, and beyond that, some authors seem eager to make politically significant claims.

We've recently seen the application of extremely sophisticated math to economics end in disaster. It wasn't that the math wasn't good, it's that the application of the math wasn't right. (I.e., it was a two-level problem). People were right to be skeptical, it turns out, but the skeptics at the time were ridiculed as innumerate fossils. (Not ridiculed by everyone, but the avant-garde mathematical economists were pretty cocky).

By John Emerson (not verified) on 23 Feb 2010 #permalink

The babies/bunnies problem is one I have struggled with for a long time, and I'm glad to see it's not just me.. I don't find babies cute in general, and I find children aged, say, 6-25 kind of repellent. They hold a special place in my general misanthropy (I'm working on it). That's not to say that I don't like particular kids, but I certainly feel no general appreciation for larval humans. And, by the way, my female wife feels the same way--if anything more strongly than I do. That said, I find many animals irresistibly cute and pleasant to be around--I have no problem with a litter box but will never touch a diaper.

If I was forced at gunpoint to make up an evo-psych explanation for bunny love, I would say that humans are instinctive naturalists and it is adaptive to be interested and knowledgeable about local fauna. However, without being at gunpoint there is very little I would ever try to explain with evo-psych. (Contra the "natural naturalist" hypothesis, my great shame as a biologist is that I am unable to stay awake in any seminar about plants: bacteria, fungi, animals--fine--but I am bored to death by plants, arguably more important to our natural history than animals.)

Anyway, evo-psych has made an academic industry out of the vaguely plausible without doing the hard work of accumulating supporting evidence. Partly because they make claims that are untestable. If you just make up pat, untestable explanations for things then you have to start wondering if you're a scientist. It's an is-ought quagmire, and a lot of them seem willfully oblivious to it. Maybe due to a another logical fallacy: a lot of people buy our books, so we must be doing something right.

Razib: Brilliant phrase, with much wider application, "much of the evo-psych which penetrates the broader public mindspace is driven by demand-side forces." Substitute "evo-psych" with the difficult issue of the hour (ecology, living green, traffic, varieties of danger, race, people who aren't like "you, taxes and spending, evolution, global warming, etc.

At least evo-psych ideas are tested and refined constantly, no Freudian just so stories. Evo-psych is dangerously anti-egalitarian so that will make sure it will be contested ferociously, which, ironically, will benefit EP, because it will push scientists to think harder, critically rethink all the time.

Less Wrong is an interesting blog, btw.

The "gay gene" business has been something that I've hammered away about in the past so I think I'm morally obligated to mention my tentative view of the thing now that it's been offered to me in this acceptable forum.

I would assume that this view would pretty much be agreed upon by pretty much everyone here but it's worth mentioning nonetheless because I never (ever) see it stated explicitly.

It's likely that environmental factors combine with innate tendencies to make a guy choose to identify as "gay". That being the case, people who find self-identified gays abhorrent and/or fear that their sons may choose to define themselves as such have every right to try and change the culture and thus are likely to find far fewer "gays".

As of now I do not believe that there is a large percentage of the male populace who are born with innate strong romantic and sexual feelings for men and with no such feelings for men (once they hit puberty of course) but that the belief in the existence of such a class is a myth that tends to CREATE it.

There are certainly SOME people who would feel this way regardless of the environment and social myths that surround them but those people are likely but a small fraction of a single percent. The majority of the people who self-define as Calvinistically homosexual are people who likely ended up with that self definition ONLY because of the unique beliefs of our culture but would not have ended up that way were they raised in America in the 1950s.

I don't mean that Millennial "True Gays" would have been closeted gays in the 1950s but that the majority of them would likely be happily married and not have many homosexual inclinations at all.

The thing has too many variables for me to enumerate here in a blog comment so I'll just return to reiterate the basics.

It seems very likely that the recent "normalization" (and fetishization and heroification and celebration) of Born Gays, as though they were Born Black or Born Female, has led to a tremendous uptick in the number of men (and it goes without saying, women) who truly believe themselves to "Be Gay".

Thus, while I honestly don't care much about where people put their penises, I feel that the Left here is engaged in a decades-long Big Lie that should be fought harshly, simply and only because it's such a socially successful lie (like religion, race-denialism and other socially successful lies).


"At least evo-psych ideas are tested and refined constantly..."

How are evo-psych ideas tested? Here are some specific claims:
-Athletes wearing red win more often because red signifies male fitness
-People are rude to strangers because pleistocene humans lived in small groups where you knew everyone by sight
-[insert any performing art or consumer product] is a product of sexual selection

How would you "test" any of these claims?

There are some general claims of EP, a couple of common ones:
-Human cognitive capacities are modular and evolved for specific adaptive purposes in human prehistory (but usually not earlier for some reason).
-Apparently maladaptive modern behavior can be explained by modules that evolved under different, earlier conditions.

I would be very interested in any sign that evolutionary psychologists are actively accumulating evidence to support these general claims...my impression has always been that they are treated as axiomatic. Given that we know next to nothing about the social conditions under which prehistoric humans or earlier hominids lived, I don't know where evidence to support this would come from.

I have more...

"Evo-psych is dangerously anti-egalitarian..."

Egalitarianism has nothing to do with genetics. I may have a genetic predisposition to Alzheimers--that wouldn't seem fair, but no one has ever claimed that humans are genetically equivalent. Egalitarianism doesn't claim everyone is the same or has the same abilities or faults, it claims that everyone is morally equivalent and deserves the same political/ethical/social treatment, regardless of these differences.

Second, the only evo-psych claims that could suggest differences among modern groups would be those related to genetically determined psychological traits that have changed after migration out of Africa by some groups--that's very recent in hominid evolution, and you would have to assert that a significant number of our cognitive "modules" have evolved a lot in the last 50,000 years, either under selective pressure or due to drift, etc. This is currently untestable, but won't always be so.

At least evo-psych ideas are tested and refined constantly

Examples, please. I don't feel that they are.

By Nanonymous (not verified) on 23 Feb 2010 #permalink

you would have to assert that a significant number of our cognitive "modules" have evolved a lot in the last 50,000 years

That's the evo-pych argument, as I understand it, but ignores the possibility of merely altering the prominence or the distribution of these "modules" among different populations. The evolving of new behavioral traits is not necessary for there to be behavioral differences among populations.

"Egalitarianism doesn't claim everyone is the same or has the same abilities or faults, it claims that everyone is morally equivalent and deserves the same political/ethical/social treatment, regardless of these differences."

Sometimes that seems to get confused with expecting equal outcomes also.

I don't have any theories about why, in general, fuzzy baby animals seem so much cuter than human babies. But I agree that they do. However, there is an important exception. *My* (now grown) babies (and my grand baby too) were *extremely* cute(grand baby still is). Unfortunately everyone else's' kids are weird-looking, snot-nosed brats.

But of course one must be polite, and pretend they are all cute. I'm pretty sure that most people believe their own kids are adorable--other peoples' kids not so much. It is a good system and I think it benefits everyone in the long run. It is better not to try to think too much about it or beat yourself up for being irrational. This is an example of where it is useful to believe something that is not actually true.

I find that my attraction to my own offspring generalizes into feelings of good will towards other people. For example, if one of my students (I am a lecturer at a college) is having a problem or needs extra help or accommodation, I often find myself thinking that one of my own kids has been, or might have been, in a similar situation, and this tends to make me sympathetic and helpful. Sometimes I think about my students' parents, and about what their hopes and dreams are for their offspring. It makes me feel like sh*t when I have to fail someone.

Now that my own kids have grown up, and my grand baby lives in another city, I am even more attracted to fur-kids. I've got pugs on my lap now as I type this. Sometimes I joke that my kids are lucky I didn't know how cute and cuddly pugs were before I had babies. But I think it is just that I'm at a different stage of life now.

I've often wondered why pets are more popular in some cultures than in others. Could this be HBD related?

mnuez, your arguments about gay gene X environment interactions could apply to any human behavior. Given that homosexual behavior is widespread in Mammalia, it is as likely (and I believe true) that all of our categories of sexual activity and relationships (e.g. marriage) are derived from our cultural environment, not just gay ones. (And engaging in homosexual behavior does not preclude reproduction, in case anyone is still making the blanket maladaptivity criticism of a role for genes in homosexuality.) So it comes down to: 1) there is genetic variation that affects most behavorial traits; 2) the specific manifestations of this variation are determined by the environment. So what? I don't get what is special about homosexuality.

Melykin, I think you're right that I would be slavishly in love with my own offspring, thanks to some pretty solid genetic wiring. That's an EP claim I can buy: we are wired to invest in and protect our own offspring. Because it's not an EP claim, it's a widely observed and well understood branch of animal biology. The generalization to a master cute button run amok to explain love of animals is what's pushing it, and pointless.

ziel said: "The evolving of new behavioral traits is not necessary for there to be behavioral differences among populations."

That's true, but I have never heard any convincing argument for distinguishing between these two hypotheses: 1) Humans have evolved a general plastic brain that can fit easily into a broad (if you consider the diversity of human cultures broad) range of cultural and environmental conditions....or 2) Different cultural/environmental conditions have altered human psychology in different groups via selection.

As I've said elsewhere, the strong selective pressures on human populations seem to have been related to diet, disease, and climate--these are selective sledgehammers. I have a hard time imagining stable, strong pressures on psychological traits, particularly given that they are so inherently plastic already (cue the Baldwin effect). That said, genes that affect these traits can vary due to drift or pleiotropy, so I am not arguing that it is impossible for psychological traits to vary, just that it's unlikely (and there is no evidence) that they have been subject to recent selection. Which is why it's so annoying that it is the underlying assumption of an entire field.

"It would be nice to do a survey of the rejection of specific behavior genetic results as a function of ideological differences."

Another thing that would be interesting would be to look for association between genetic variants and rejection of behavior genetic results.

And engaging in homosexual behavior does not preclude reproduction, in case anyone is still making the blanket maladaptivity criticism of a role for genes in homosexuality.

It does not preclude reproduction, but is there as much reproduction? If it's less - even a little less - then it's probably maladaptive.

Miko - you don't think disease and climate have profound impacts on behavior?

"If it's less - even a little less - then it's probably maladaptive."

Yet has been observed in over 1000 species of animal.

"Miko - you don't think disease and climate have profound impacts on behavior?"

Yes I do; I don't think they have recently exerted strong selective pressure on the genes underlying human behavior.

Yet has been observed in over 1000 species of animal.

Homosexual activity I take it you mean. But obligate homosexuality? I doubt it very much.

"But obligate homosexuality? I doubt it very much."

So what? If "obligate" comes down to preference, you've got nothing. I'm not claiming there isn't a cultural component--in fact I'm claiming the specific categories are purely cultural--I'm just saying homosexuality is well within the normal mammalian behavioral repertoire. "Obligate" homosexuality is no stranger than the choice to skip reproduction all together.

So...because people find rabbits cute in absence of a need to do so, the idea that there's a genetic component for why we find things cute, what kinds of things we find cute, or even if we find things cute, is just to be discarded? I don't think that's what the author of the blog Less Wrong is intending.
I could be misreading the comments by Miko, but I just don't see a reason to discard EP as a school of thought, altogether. I must confess that I don't have the background to speak authoritatively on this subject, but since that wasn't a pre-requisite for commenting, and I'm interested in learning, I'll throw my question out there: why wouldn't there be a genetic component to things such as behaviors that are that trans-cultural? And if there isn't, what would be completely replacing it?
I can't think of any culture for which the chastity of a family's teenage son is of any interest, but many cultures have great interest in preserving the teenage daughter's chastity. I wish I could remember the EP proponent who brought that up, for it's not my idea, and I'd prefer to give him credit for it. Also, what culture finds bilateral asymmetry more attractive than bilateral symmetry, for both face and body? What other kind of description would others think better provides a foundation for it?
I do agree with Less Wrong in pointing out, though, that there's a hell of a lot of complexity for modeling humans and it's not something that is particularly easy to do. In any case, I'm not one to go against EP categorically, but I find it's Kool-Aid more helpful in explaining what people around me are doing than most other things have been. If there's a better flavor, though, I'll drink that one, instead.

By Mylasticus (not verified) on 01 Mar 2010 #permalink