In today’s New York Times book review, Robin Marantz Henig reviews a new book on evolutionary psychology by Paul Bloom, How Pleasure Works. I haven’t yet read this book, but the review indicates that it may be a more reasonable specimen of the genre, seeing the human penchant for pleasure-inducing activities as a nonadaptive byproduct, or spandrel, of other evolved tendencies. But there’s a slight problem with the review. Can you spot it?
Pornography is another example of pleasure via essentialism. Why do some men spend more time looking at Internet porn than interacting with flesh-and-blood lovers? There may be “no reproductive advantage” to liking pornography, Bloom writes, but there is an advantage to its source: an urge to look at real-world “attractive naked people,” which makes us want sex, which in turn is good for continuation of the species. Pornography uses the same pleasure mechanism as actual sex, which is handy since “there aren’t always attractive naked people around when you need them.”
The paragraph contains one of the most common misconceptions about evolution: that traits evolve because they’re “good for continuation of the species.” (This is probably Henig rather than Bloom’s misconception.)
This isn’t the way that most traits evolve under natural selection. They evolve not because they help the species to persist, but because they help the genes to persist. Or, more accurately, selection favors those traits that enhance the survival and reproduction of the genes that produce those traits. Genes that make us want to have sex (and, as a byproduct, make us look at pornography that can gratify the sex drive) are favored because individuals that carry them have more offspring than those with sexual lassitude. This says nothing about the good of the species as a whole, but about the good of individuals and the genes they contain.
Indeed, sex may be a trait that reduces the persistence of some species or groups. This is because most sex requires two individuals to reproduce, and it may be hard in some circumstances for two individuals to find each other. If population density is sparse, perhaps because individuals live in marginal habitats, the need to find somebody else to mate with may not be as adaptive as those forms of reproduction (say, parthenogenesis) that enable you to reproduce without a partner. This may explain the observation that asexual species often occur in marginal or disturbed habitats.
Natural selection may occasionally favor the evolution of traits that favor the persistence of groups (“group selection”), though I don’t know of any such traits. And selection can operate directly on the genes themselves, as in the phenomenon of “meiotic drive”, in which one form of a gene outcompetes another because it’s better at getting into the sperm during cell division. There’s also “kin selection,” in which behaviors like parental care can evolve that may be deleterious for an individual but useful for its offspring or kin.
But must evolutionists think that the main level on which selection operates is that of individuals, not groups. It is the differential success of individuals, not groups, that causes the spread of the genes they contain.
Remember that the next time you see a nature program on television that explains some behavior as having evolved “for the good of the species.” They’re invariably wrong.
21 Comments
I am a bit confused, “group selection” says that competing mates don’t kill each other because it is bad for the survival of the species, and that is wrong according to John Maynard Smith, and certainly Dawson bees ” won’t hear of that”,but is that the old definition of group selection?
So traits evolve, because they are good for the continuation of the genes – to be more adaptive. But those genes could be expressed on the level of the individual and on the level of maybe a genus????
Natural selection may occasionally favor the evolution of traits that favor the persistence of groups (“group selection”), though I don’t know of any such traits.
Oh ya, it’s like totally obvious, dude – religion. Nicholas Wade says so in The Faith Instinct (funded by a “generous grant” from the Templeton Foundation). He says so a lot. It’s pretty much the whole book (funded by a “generous grant” from the Templeton Foundation).
Sounds like “funded by a “generous grant” from the Templeton Foundation” is a code word for BS?
… oh, of course!
As I see it, group selection cannot provide any kind of adaptation, but can preserve adaptations in the long run.
Sex, for example, or segmentation. Each has to evolve through gene selection within a gene pool. But over time, those gene pools which have inherited sex or segmentation (or any other broad trait, like four limbs) may survive preferentially, compared to those pools which lack the traits.
Think if it like a tournament. The teams involved win due to a mixture of luck and members’ skills. If the tournament is long enough, luck averages out, and you end up with better teams progressing further.
It would be absurd to claim that the tournament itself is in any way responsible for the quality of the teams. It’s just the nature of a tournament that there will be winners and losers over time, no matter how strange the rules are (i.e. a “winner” could be whichever team went the longest without eating chocolate ice cream, and weren’t told this in advance – winning teams would have a pre-existing tendency to not eat ice cream).
But if “group selection” is another word for contingency (of not going extinct), I don’t see how it is a falsifiable hypothesis?
That is, you don’t see how it’s at all useful? I agree completely.
Oh, I see.
Religion is proof that humans don’t evolve (joke) I personally think that the story of Adam and Eve is a 20,000 myth about evolution. It reeks of change from the natural, more ‘living in the moment’ animals to the future/past ‘thinkers’ that we are. On Jerry’s point, I think it’s a simple mistake that any book reviewer could make when interpreting something in a book. I couldn’t see it without Jerry pointing it out (but I’m new here) signed – the atheist recovering alcoholic.
But how about evolution of traits such as empathy/compassion, seen in Great Apes including us? Wouldn’t their appearance be linked to group selection? It is not to see how a tribe where members cared about one another would outcompete another, where they didn’t.
Primatologist Frans de Waal seems to think that, in his book “the age of empathy”.
A tribe with members who help each other and join together against opponents would enjoy more individual reproductive success than one with excessive infighting. No problem for individual selection. Besides, are you saying there isn’t individual competition for mates in groups of primates?
The problem is that things like empathy and compassion are beneficial to the individual (especially so if you count the “individual” as the gene) as well as the population as a whole.
The question is whether traits can evolve that benefit the group but do not benefit the individual.
It seems plausible that such traits could evolve if they were neutral to the individual and just got fixed in the population, but I can’t think of anything like that.
Even then, let’s say you did get a population selected for against other populations of the same species because its members had some trait that was beneficial to the group. Now what? Without selection pressure to keep that trait around at the individual level, seems like it’d just go away over time.
Ah, that hit the spot! _Of course_ “groups” aren’t necessary behaving analogous to “members of a population” in the needed sense. Between Tulse and you there’s not much left, is it?
Genes that make us care for other things that seem to have feelings like we do ensure their own survival… We care more for people/animals that are seen to care for their young and/or express happiness or pain in ways that we recognize. (Some people manage to care for cephalapods despite their complete lack in this area, but they are an anomaly.)
It’s probably similar genes and brain structures the account for our caring for other things that seem to care. Oxytocin seems to be a primary chemical involved.
Genes involved in caring induce their vectors (such as us) to preferentially aid the survival of other vectors that carry the same “caring genes”. The gene is still selfish…
“Caring” behavior helps ensure the survival of “caring” in those we care for.
The gene doesn’t have to service the vector that copies it… it only has to ensure that vectors that carry copies of it preferentially survive and reproduce.
So “care for things that care” could be information that favors group selection, but not necessarily the individual. It would help offspring survive, but it would also explain our tendency toward preferences of certain kinds of pets and their survival… it helps explain blood donation and other forms of altruism and our observation of animals nursing offspring of other species or forming friendships with such.
OK, I guess I can understand how pornography might put a person in a mood more likely to lead to procreation.
But the following assertion that there might not be attractive nude people around after I watch pornography raises certain questions.
How does my pornography-stimulated libido do anyone any good if there is no suitable sex partner around?
And why am I wasting my time looking a porn if “attractive nude” persons are equally handy?
Every study I’ve ever seen of pornography suggests that its primary effect is to lead to masturbation, which is harmless and fine, but isn’t likely to produce babies.
This all strikes me as the worst sort of armchair psychology.
> “But there’s a slight problem with the review. Can you spot it?”
Yeah, it reeked of Kiplingitis. In other words, his explanation of man’s liking pornography was a Just-So story. Oh wait, that was a critique of Bloom, not Henig.
“Evolutionary Psychology as Maladapted Psychology
Robert C. Richardson
Human beings, like other organisms, are the products of evolution. Like other organisms, we exhibit traits that are the product of natural selection. Our psychological capacities are evolved traits as much as are our gait and posture. This much few would dispute. Evolutionary psychology goes further than this, claiming that our psychological traits—including a wide variety of traits, from mate preference and jealousy to language and reason—can be understood as specific adaptations to ancestral Pleistocene conditions. In Evolutionary Psychology as Maladapted Psychology, Robert Richardson takes a critical look at evolutionary psychology by subjecting its ambitious and controversial claims to the same sorts of methodological and evidential constraints that are broadly accepted within evolutionary biology.
The claims of evolutionary psychology may pass muster as psychology; but what are their evolutionary credentials? Richardson considers three ways adaptive hypotheses can be evaluated, using examples from the biological literature to illustrate what sorts of evidence and methodology would be necessary to establish specific evolutionary and adaptive explanations of human psychological traits. He shows that existing explanations within evolutionary psychology fall woefully short of accepted biological standards. The theories offered by evolutionary psychologists may identify traits that are, or were, beneficial to humans. But gauged by biological standards, there is inadequate evidence: evolutionary psychologists are largely silent on the evolutionary evidence relevant to assessing their claims, including such matters as variation in ancestral populations, heritability, and the advantage offered to our ancestors. As evolutionary claims they are unsubstantiated. Evolutionary psychology, Richardson concludes, may offer a program of research, but it lacks the kind of evidence that is generally expected within evolutionary biology. It is speculation rather than sound science—and we should treat its claims with skepticism.”
http://mitpress.mit.edu/catalog/item/default.asp?ttype=2&tid=11255
Comments like that might just be a slip of the tongue, it’s wrong but it’s a really difficult concept (at least as far as I can tell) to express succinctly.
Jerry, you seem to contradict yourself at the end. You emphasize genes genes genes, and then say that individuals are the most important, right after you appear to dismiss kin selection (entirely valid) in the same paragraph as group selection (controversial at best). As nature is replete with instances favoring genes over individuals, this post is going to mislead or confuse a lay audience.
It would be more correct to say “the easiest and most common way for a gene to enhance its own reproduction is to directly enhance the reproductive success of any individual that carries that gene”, thus keeping emphasis on the gene.
Has anyone besides me ever heard of the book Mutual Aid by Peter Kropotkin?It seems obvious to me that when say for example wolves cooperate in hunting they are assisting,and aiding the ability of the alpha wolves to reproduce.There are examples of cooperation and interaction all over the animal world.Of course,there is also competition.But why this blind spot to extant cooperation?Is it a cultural prejudice?
Aren’t there a goodly number of traits – a high proportion, even – that may originate in an individual (as they have to do) but must spread through the species somewhat before they can be beneficial? Many of the behaviours of eusocial animals would be of no benefit to any of them till more than one were doing them. EG, the fanning of worker bees. (And the workers are sterile and the drone and queen that first originate the mutation don’t even express the behaviour…) Hmm, my head it starting to spin.
There is no blind spot to cooperation in behavioral ecology. Instances of apparent altruism/cooperation-without-direct-benefit are exactly the reason that evolutionary theories of kin selection and game theory were developed. Wolf packs are easily and parsimoniously explained by inclusive fitness theory, which is generally gene-centered.