Sex at Dawn

I ordered Christopher Ryan and Cacilda Jethá’s Sex at Dawn from Amazon shortly after Dan Savage pimped it on his weekly podcast. I was intrigued by the idea of an evolutionary account of human sexuality that differs from the typical account offered by evolutionary psychology. Sadly, I was underwhelmed. Here’s what I wrote in the comments of a Dan Savage blog post on the subject about three weeks ago:

Dan, I love you, your column, and your podcast. But I'm reading Sex at Dawn -- because you suggested it -- and speaking as an academic, I'm not impressed. I'm having a hard time even finishing it, because on every single page there's an unsupported assertion, straw-man argument, or cherry-picked example that makes me want to throw it at the wall.

If you're looking for scientific support for your anti-monogamy position, you can find it in the *traditional* account in evolutionary psychology -- the one that Sex at Dawn tries so hard to debunk. The traditional account does not say that monogamy is easy. On the contrary, the traditional account says that cheating (in the sense of straying from monogamous relationships) is to be expected for evolutionary reasons. It is, as you say so often on your show, perfectly natural for people to want to have sex with people other than their primary partner.

Of course, it's also perfectly natural for people to get jealous. There are good evolutionary reasons for that, as well. It may seem hypocritical to be a jealous cheater, but natural selection does not breed for consistency -- it breeds for reproductive advantage. When the authors of "Sex at Dawn" say their story is more parsimonious, what they mean is that it paints a simple picture of human psychology that requires no hypocrisy. But we are hypocritical, so their explanation doesn't fit with the messy psychological reality. And that's an insight that will actually help your advice-giving career. People make a lot more sense when you understand their built-in contradictions.

When you're giving people advice on sex and relationships, you have a very critical eye. You should cast that same critical eye on the books you're pimping.

I’ve finished the book now, and my opinion hasn’t changed.

What most disappointed me was the authors’ deliberate conflation of Victorian values with modern evolutionary psychology, as though they were exactly the same position. By so doing, they make it sound as though any refutation of the former were also a refutation of the latter. They spend precious little time exploring the very significant differences between the faith-based position of the Victorians and the science-based position of the evolutionary psychologists. Every time they cite Victorian-types taking an absurd position on the subject of sex, they invite us to conclude that evolutionary psychologists share in the absurdity. By the end, they come close to saying evol psych is responsible for male and female genital mutilation.

The authors also spend a great deal of time glorifying the lives of primitive peoples, leading us to believe our distant ancestors led long happy lives filled with nutritious food and plenty of sex. Yet they also try to distance themselves from the “noble savage” position, saying (for instance) that “[t]hese pre-agricultural societies were no nobler than you are when you pay your taxes or insurance premiums” (p. 9). But that’s just a dodge. Ultimately, they really do glorify primitive living conditions. Consider, for instance, their approving quote from Kurt Vonnegut (p. 149): “Human beings will be happier – not when they cure cancer or get to Mars or eliminate racial prejudice or flush Lake Erie but when they find ways to inhabit primitive communities again. That’s my utopia.” Ryan and Jethá apparently agree.

Their overarching argument has numerous weak spots, but the weakest is their analysis of jealousy. Jealousy matters because it’s a key point on which their “promiscuous primitives” hypothesis differs from the standard account, which says that (a) males will be jealous of other males because they reduce paternity certainty, and (b) females will be jealous of other females because they threaten their children’s share of male-provided resources. But if primitive people really did mate in a polyamorous fashion in a context of abundant resources, as the authors of Sex at Dawn claim, then they need a compelling story on the origin of jealousy. Yet their argument boils down to the claim that jealousy can be controlled with appropriate social norms. Which is true; so can most human emotions. But that does nothing to explain why jealousy is there in the first place, nor why such strong social norms are needed to keep it in check.

The authors refute the claim that women have lower sex drive than men by noting, more than once, that strong social norms have been instituted to keep it down. “Why the electrified high-security razor-wire fence to contain a kitty-cat?” they ask (p. 39). On this point, I think they have a reasonable claim, and female libido may indeed be naturally higher than is typically recognized. But the same line of argument can be directed at their own position on jealousy. If jealousy is not a natural impulse, then why are such strong social norms required to control it?

The overarching flaw in Ryan and Jethá’s approach is the either/or mentality they apply to a wide range of questions. Humans are either more like chimps, or more like bonobos. (Why can’t we have characteristics of both, as well as some characteristics unique to us?) We are either naturally warlike or naturally peaceful. (Why not a tendency to keep the peace locally while making war with strangers?) We evolved in a context of either abundance or constant scarcity. (Why not stretches of both?) We are either relentlessly selfish or fully altruistic. (Why not guardedly altruistic with a tendency to exploit opportunities for selfish gain?) We are either faithfully monogamous or highly promiscuous. (Why not generally monogamous with opportunistic exceptions?) On all of these questions, Ryan and Jethá take the latter position – and then support it by showing exceptions to the former. Ultimately, the whole book reads like an extended lesson in how to commit the fallacy of the excluded middle.

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Darwin Awards Imposter

The 2007 Darwin Awards have been announced, but if you think you’ve read them, you may be mistaken. Here is the list forwarded to me by email, and the winner sounds like the real deal:

When his 38-caliber revolver failed to fire at his intended victim during a hold-up in Long Beach, California , would-be robber James Elliot did something that can only inspire wonder. He peered down the barrel and tried the trigger again. This time it worked.

Assuming that Elliot died from the blast, this story satisfies the Darwin Awards’ original goal of “honoring those who improve the species… by accidentally removing themselves from it!” But if you read the rest of the list, you’ll find that none of the runner-ups actually died (or rendered themselves impotent, which is just as good from an evolutionary perspective). You might even call these the Anti-Darwin Awards, insofar as the subjects' survival raises questions about the efficiency of natural selection.

As it turns out, this same list was circulated in 2005, and a number of its entries were debunked as urban legends.

The actual winner of the 2007 Darwin Awards killed himself by giving himself a liquor enema. But I prefer the first runner-up, which was actually a team effort:

June 2007, South Carolina | A passing cabbie found a 21 year-old deceased couple laying naked in the road an hour before sunrise. Authorities were baffled. There were no witnesses, no trace of clothing, and no wrecked vehicles present. But investigators eventually found a clue high on the roof of a nearby building: two sets of neatly folded clothes. Safe sex takes on a whole new meaning when you are perched on the edge of a pyramid-shaped metal roof. "It appears as if [they] accidentally fell off the roof," Sgt. McCants said.

You can read the full list of genuine 2007 Darwin Awards here; accept no substitutes.

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Psychopaths as Hawk Strategists

I recently stumbled on a year-old article about psychopaths. The article offers various explanations for why psychopaths exist, but this one I found most interesting:

Evolutionary psychologists regard psychopathy as an inherited personality style that has evolved because glib, deceitful individuals—as a minority within a larger population of trusting folk—often reproduce with much success.

So in other words, psychopaths are Hawks in the Chicken game of life. What’s nice about this explanation is that it not only explains why psychopaths exist, but also why we’re not all psychopaths. If there are few enough psychopaths in the population, then being a psychopath makes sense because you’ll mostly have winning confrontations with nice people. But if there are too many psychopaths, then the gains from taking advantage of nice people will be swamped by the losses from confronting other psychopaths. In equilibrium, you’ll get both psychos and nice folks, with each strategy generating approximately equal returns, and with the precise balance determined by the relative payoffs of different interactions.

With that explanation on the table, I found this one less plausible: “Other investigators ... regard psychopathy as the result of a still-unspecified genetic disorder. The inherited defect interferes with the workings of the brain's emotion system, which is centered in the amygdala, a structure especially concerned with perceiving dangerous situations.” Possible; but if psychopathy is a genetic defect, you have to wonder why it hasn’t been more completely weeded out of the population. Genetic defects can persist, of course, but usually because they produced some kind of balancing benefit in some evolutionary environment – e.g., the heterozygous form of sickle-cell anemia provides some protection against malaria. So when I see an alleged “defect,” I always look for the adaptive explanation.

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Feminism and Evolutionary Psychology

Via Jane Galt, I find Todd Seavey’s lengthy diatribe against feminism. There’s too much there to sum it up with a simple “this is all true” or “this is all nonsense.” Some is right, some is wrong, some is confusing... but all of it is fun. I laughed out loud several times while reading it. Here’s my quick breakdown:

On charges #1 (feminists make a priori assertions about empirical matters) and #2 (feminism is vague and ill-defined), Seavey’s right on target.

Charges #8 (feminism justifies its existence using worst-case scenarios) and #9 (feminism is ideological cover for self-interested special pleading) also make a lot of sense, though Seavey overstates his case a bit.

Charges #6 and #7 (neither of which I can summarize easily) both come off, intentionally or not, as whining about the decline of traditional marriage and the emergence of more permissive social norms.

Charges #4 and #5 are the most fun, albeit very debatable. Seavey applies a stripped-down evolutionary psychology model to explain female behavior. I’ll strip it down further: Women seek to mix their genes with the best possible sperm sources, and that means flocking to the alpha males. If they can’t manage to snag one of those, they’ll settle for a regular schmoe instead (and maybe – Seavey might have added but didn’t – dupe that schmoe into providing for some alpha cad’s baby).

Simplistic, but probably not far off the mark. What’s odd is Seavey’s shorter, and less nuanced, characterization of male behavior:

And, yes, some small minority of men will calculate — or simply feel on a gut level, as a result of instincts produced by evolution’s mating calculus — that they have a better shot at flourishing in a competition to become the pimp-daddy themselves than in a culture that strongly encourages permanent pair-bonding. But most males, I think, simply want an acceptable, normal girlfriend.

In trying to draw the sharpest possible contrast between men and women, I think Seavey’s missing the symmetry here. Just as women seek the alpha males but settle for the regular guys, men seek pimphood but settle for the pair-bonding. Of course, Seavey’s right that only a small minority of men actively seek to maximize the number of women they bed. But cheating is widespread, not just a privilege of the alpha males.

Still, he’s correct to focus more on the asymmetry between male and female mating strategies: “Any honest examination of human life ought to start from this evolutionary psychology insight about the differential behavioral implications of wildly different sperm and egg production/usability rates.” The fact that men have virtually unlimited capacity to produce children, whereas women’s capacity for child-bearing is severely limited (one pregnancy at a time with substantial associated costs), creates a divide in reproductive strategies: men are r-selected while women are K-selected. That is, men’s reproductive fitness is maximized by spreading their seed far and wide, while women’s reproductive fitness is maximized by making substantial investment in a small number of offspring. A natural corollary is that women have to be more picky about their partners (if you’re only going to mix your genes with a handful of men, you gotta pick the best ones) whereas men don’t have to be as picky (mixing genes with a low-quality woman does not generally preclude mixing genes with a high-quality woman). Hence the tendency for women to be “hos” (Seavey’s terminology) by flocking to the highest-status males. But men are hos, too, just in a different way.

(And I should add, just for completeness, that these are all broad generalizations. Individual men and women vary substantially around the biologically-embedded norm, and culture certainly affects the expression of innate tendencies.)

Definitely fun material, and if feminism stifles this kind of discussion with a dogmatic insistence that all male-female differences are purely cultural in origin, then so much the worse for feminism. But I somehow think there’s room for a realistic feminism that admits the biological and psychological differences between men and women.

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Evolutionary Biology and the Libertarian Paradox

Tyler Cowen enunciates what he calls the “paradox of libertarianism”:

Libertarian ideas also have improved the quality of government. Few American politicians advocate central planning or an economy built around collective bargaining. Marxism has retreated in intellectual disgrace.

Those developments have brought us much greater wealth and much greater liberty, at least in the positive sense of greater life opportunities. They’ve also brought much bigger government. The more wealth we have, the more government we can afford. Furthermore, the better government operates, the more government people will demand. That is the fundamental paradox of libertarianism. Many initial victories bring later defeats.

There is something to this. Human beings seem to have some kind of built-in compassion gene that leads us to want to help others in times of abundance. There are good evolutionary reasons for that to be the case, a point that Paul Rubin emphasizes in his book Darwinian Politics (which figured prominently in a Liberty Fund event I attended recently). What is not so obvious is why this biological impulse should cash out in terms of policy – especially national policy. The human desire to help others was born of our origin in small groups and clans, most likely consisting of no more than a few hundred people at most. And notably, it’s in small-group contexts that charity is most effective, because it’s much easier in a small group to monitor the recipients for signs of shirking and moral hazard. It’s at least odd, then, that the compassionate impulse would manifest itself in modern society as a desire to help a “family” consisting of millions of people.

I suspect that while the compassionate impulse is innate, its zone of application is malleable by culture. We have “nationalized” our compassion only because of historical factors that have aggrandized the nation-state over smaller political units, communities, churches, extended families, and so on. If I’m right, then it might be possible to redirect those impulses back toward the smaller groups where they are both less damaging and more effective.

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Lice DNA

Read here about how a scientist used lice DNA to pinpoint when human ancestors finally lost their body hair.

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Laughter, Prison Rape, Political Correctness, and Signal Extraction

Thanks to Ezra Klein and Glenn Reynolds, the prison rape problem is getting some much-needed attention in the blog world. At Unfogged, Fontana Labs (pseudonym) says, “I'm so ashamed to have joked about this.”

Prison rape is a real problem that deserves to be taken more seriously. I’ve written about “the rape penalty” twice before (Glenn links to the former post). That said, I can’t really feel guilty about making the occasional joke about prison rape. As my friends (especially my co-blogger) will tell you, I’m willing to joke about pretty much anything, and I don’t feel bad about it. To see why I think it’s okay, it’s worth knowing something about the evolutionary origins of laughter. One of the more widely recognized functions of laughter is to release stress and anxiety produced by fear or danger.

The relief theory is the basis for a device movie-makers have used effectively for a long time. In action films or thrillers where tension is high, the director uses comic relief at just the right times. He builds up the tension or suspense as much as possible and then breaks it down slightly with a side comment, enabling the viewer to relieve himself of pent-up emotion, just so the movie can build it up again! Similarly, an actual story or situation creates tension within us. As we try to cope with two sets of emotions and thoughts, we need a release and laughter is the way of cleansing our system of the built-up tension and incongruity. (According to Dr. Lisa Rosenberg, humor, especially dark humor, can help workers cope with stressful situations. "The act of producing humor, of making a joke, gives us a mental break and increases our objectivity in the face of overwhelming stress," she says.)

In short, we sometimes laughter precisely because we recognize that something is terrible or wrong. It’s the healthy alternative to feeling fearful or angry all the time; there’s really something to the old saying, “If I didn’t laugh, I’d cry.” In my case, I can find humor in prison rape precisely because it’s so appalling.

A second function of laugher is to draw attention to incongruity:

The incongruity theory suggests that humor arises when logic and familiarity are replaced by things that don't normally go together. Researcher Thomas Veatch says a joke becomes funny when we expect one outcome and another happens.

This function of humor helps to explain why professional comics so often dwell on race, sexual activity, and excretory functions: discussion of these topics is inherently incongruous with everyday experience because of their taboo nature. A lot of the humor arises simply from the fact that we are unused to talking about such things in polite company. Prison rape fits this criterion as well.

So why do we also regard laughter about certain topics as socially unacceptable? Probably because laughter serves a third function as well: to establish superiority.

The superiority theory comes into play when we laugh at jokes that focus on someone else's mistakes, stupidity or misfortune. We feel superior to this person, experience a certain detachment from the situation and so are able to laugh at it.

Hence the opposition to jokes about race, sex, sexual orientation, etc. The fear is that people who laugh at members of other groups is expressing a feeling of superiority to that group – the kind of superiority that could create the detachment needed to indulge one’s actual bigotry. This function of humor probably also plays a role in jokes about prison rape; most free citizens tend to feel superior to those who have been incarcerated.

The problem, then, is one of signal extraction. Laughter serves primarily as a social signaling mechanism that helps to bond people together. It can bond them in shared relief from fear or danger, in shared recognition of incongruity, or (less laudably) in shared feelings of superiority to outsiders. But when interacting with someone whose intentions are unclear, it’s hard to trust that they’re laughing for acceptable reasons. I can only hope that my friends and family, who are on the receiving end of my joke-telling, know the right signals to extract.

I think it’s also worth noting that political correctness may have made some kinds of jokes funnier than they were before. Political correctness has successfully removed certain attitudes about race, sex, ethnicity, etc., from the realm of acceptable discourse – often justifiably so. But hearing those attitudes expressed aloud is now much more inconsistent with everyday experience than it used to be – and as a result, they are more likely to trigger the incongruity-sensing function of laughter.

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Canine Evolution

I found this L. A. Times article fascinating. Apparently, millennia of interaction with humans have shaped the genetic code of domesticated dogs in surprising ways.

In the genetic journey from wolf to lapdog, dogs developed a unique genius for sensing human intentions, as the interplay of handler and hound shaped the biology of canine behavior in ways that scientists only now are beginning to understand, new research shows. … From birth, dogs are fluent in the human text of hand gestures and facial expressions. Their ability to understand humans is better than chimpanzees -- humanity's closest relative -- or the gray wolves from which dogs are descended, according to the first direct comparison of the species.

What's most intriguing to me about this (though the article doesn't discuss it) is that it blurs the line between natural selection and artificial selection. Symbiotic relationships are a well established part of biological evolution, and nobody would suggest that those birds that instinctively pick the teeth of hippos are the result of the hippos' attempts at artificial selection. So what, exactly, is different about the relationship between humans and dogs? Is it the fact that people have *deliberately* bred dogs to have certain traits? That's true, but this article draws attention to the many traits of dogs that arose from interaction with humans without deliberate human selection, but as a corollary to it. Dogs with a greater ability to sense human needs and emotions were more likely to survive, even if humans didn't specifically try to breed in those abilities. So where does artificial selection end and natural selection begin (or vice versa)?

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