Evolutionary Cognitive Neuroscience: The Revenge

Great Debates
#1

This is in response to alterego, who wanted a thread solely on the topic. He began with an argument about the evolutionary basis for religion. I answered that there was no evidence for his theory and ample evidence against it. The debate will, I hope, be continued here.

I made my stance on evolutionary psychology known in this thread, that stance being that it’s a load of crap. The main points being:

  1. Any child can tell the difference between traits we choose and traits we don’t choose. Eye color, hair color, height, shape of nose, number of legs: these things are inherited, and no amount of will can change them. On the other hand, behaviors such as mating habits, intellectual life, and emotional attachments result from our choices. We can (and often do) choose to change our minds about all those topics. Since our genome remains the same throughout our life, this can’t be explained by our genes.

  2. None of the genes in question have ever actually been found. Thousands of scientists at numerous labs all over the world have poured billions of dollars into matching genes with traits. The genes for numerous physical traits have been found, as have some genes for brain structures, but none for the traits that evolutionary psychology demands.

  3. Evolutionary psychology assumes that genes can do anything. If you can imagine the behavior, there’s a gene for it. But genes are not magic. They are bits of DNA that encode for proteins. There’s no explanation for how a protein would create the very precise behaviors that evolutionary psychology demands.

  4. Lastly, those who say we’re evolved to do certain things can’t agree on what we’re evolved to do. Ask ten different theorists and you’ll get ten different and contradictory lists of traits that we inherited from our caveman ancestors, with ten different stories for how those traits came about.

The main response in that thread was on the issue of human universals. Certain traits are universal, and thus can only be explained by a common genetic heritage. As I see it there are three basic ways to establish a human universal.

A) Make it up. One such instance is recorded here.

No evidence is offered that this is a human universal. It’s merely stated and supposed to be accepted at face value.

B) Take a survey, usually quite small, of a certain group in an industrialized nation in the 21st century, and declare that the results of the survey prove a human universal. This article, for example, looks at a case where color preferences were traced back to our caveman ancestors. Women like pink because cavewomen picked berries (which are red, not pink) and men like blue because cavemen liked looking at the blue sky. This was determined by polling 200 young adults in England.

http://www.badscience.net/2007/08/pink-pink-pink-pink-pink-moan/#more-518

The result is not universal in either time or space. In other countries, such as China the “girls prefer pink, boys prefer blue” idea did not prevail at all. In fact, the opposite holds true. And as recently as the early 20th century, pink was the color for tough, manly men in England as well. So again we have a human universal that isn’t universal.

C) Lastly, some people take an official list of human universals. This one seems to be popular on the internet.

http://condor.depaul.edu/~mfiddler/hyphen/humunivers.htm

No information is given about the methodology behind the list. We’re just supposed to accept this as a list of human universals, and apparently believed that the only possible explanation for this is a common genetic heritage coming from our caveman ancestors.

Most things on the list, if not all, fall into one of two categories. There’s the things that result from straightforward logic, and there’s the things that aren’t universal. In the first category we have things such as the number two, the color black, medicine, antonyms, child care, etc… These things either exist in the physical world or are logical responses to the facts of human existence. (Children cannot care for themselves and thus need care, for instance.) Others, such as magic or gender roles, are not universal among humans.

So in short, I am not convinced by the human universal “proof” and I still see no evidence that human beliefs, preferences, and behaviors are shaped, in whole or in part, by genes.

#2

So I guess God did it, huh?

#3

Why does something that evolved need to be universal? - evolution typically produces diversity, in the big picture.

#4

I agree, evolutionary psychology is not well verified, and just about anytime someone comes up with a story about why we have certain behaviors now because of our ancestors, it’s almost certainly bullshit, but I do think genes can affect our behavior. The reason is quite simple: Our behaviors are affected by how our brains work. How our brains work is affected by its physical structure. Genes can affect the physical structure of organs. Of course, it’s unclear what kind of affects genes would have on behavior, since it wouldn’t be direct. But to say that genes can have no effect on the brain is just silly, I think.

#5

Evolutionary psychology does kind of sound like a load of crap - at least with regard to behaviors that are either very specific, and/or much more easily explained by other factors such as culture or rearing. Like the pink/blue thing, that sounds like culture. Whether you try to indocrinate your children with religious beliefs? Culture - your church will often tell you to do it, and help!

But I do think that certain broad things like intelligence may have generic factors. After all, and I’m not kidding, me and all my siblings are all of above-average intelligence, coming from parents of above-average intelligence. I do not see rearing being that big a factor in it, either.

#6

And a large percentage of the time, we fail. Why? For example, why do so many people make a decision to cut down on fatty foods and then fall off the wagon a few hours or days later? Why do powerful men often start and continue having sexual relations with a housekeeper or intern even though they know it’s likely to cause them a world of problems?

Sociobiology – or whatever it’s called these days – provides good answers to these sorts of questions.

#7

Your OP supports two theses:

  1. Not all people promulgating evolutionary psychology know what they’re talking about, any more than all people who promulgate quantum physics know what they’re talking about.
  2. Behavior is not 100% determined by genes.

I doubt you could find a single prominent evolutionary psychologist such as EO Wilson or Stephen Pinker who disagreed with either thesis.

If you address EP directly instead of addressing a straw man, you might get a more interesting thesis.

Daniel

#8

I’ll repeat my thoughts about EP from the thread that spawned this one, since I’m too tired right now to reformulate:

“I think one has to take care with appealing to evolutionary psychology – I think that, due to his intelligence, man has effectively introduced a fertile breeding ground for non-adaptive traits to proliferate, because our intelligence allows us to counter at least some quantity of reproductive disadvantages that would otherwise lead to these traits being weeded out of the population (this has at least some empiric validation in the observation that the rate of genetic change in humans has been accelerating for the last 20,000 years or so).”

However, I also want to make a couple of statements regarding some of the points in the OP:

Of course, what is and what isn’t choice is only an assertion on your part; besides, there are a number of physical characteristics that change throughout life and are most definitely genetically predetermined (I can grow a beard now, I couldn’t when I was twelve).

It may not be so simple as a single gene leading to a well-defined behaviour, firstly because most behavioural traits are actually pretty ill-defined when it comes to trying to break them down into their component parts (i.e. ‘macroscopic’ behaviours may well be composites of different ‘atomic’ behavioural traits, in such a way that different compositions of such behavioural atoms lead to different but similar macro-behaviours – if genes correspond to these atomic traits rather than the macro ones, their identification should be expected to be somewhat more difficult), secondly, single behaviours may be results of genetic interplay rather than having a singular genetic cause.

Well, some proteins are hormones, and hormones are known to be determinants in behaviour. Basically, it’s a well known fact that our biochemistry determines our behaviour, and that our genes determine our biochemistry (both not necessarily totally), from whence the whole EP idea stems. And even regardless of that, if there was no currently known explanation, that doesn’t mean that there can’t be one.

Science at its best – competing theories!

#9

Of course it might be genetic, that is not contradicted by the OP from what I can see. The nature vs. nurture argument is often misused: not many people believe that one always explains everything; they would rather disagree on the strength of each.

Your anecdote != data, how can you extract genes from environment? If one of your siblings was adopted out at a young age, then ended up intelligent, and this study was repeated by many families, ethics be damned, then there may be sufficient evidence for your theory. That said, there are probably genetic and environmental contributions to intelligence, that could be said about most things.

#10

My anecdode = datum. One datum. And, as there were five of us spread out over fifteen years, and after the first two of us the style of parenting and the structure of our environment began to change over time, so as to be quite different for each of my younger siblings, I think it’s quite reasonable, if not as the worlds smallest survey, at least as far as anecdotes go.

#11

I agree with most of this; the only thing I’ll add is that the experiment you propose has more-or-less been done, by comparing various combinations of identical twins, fraternal twins, genetic siblings, and adoptive siblings across genetic families and adoptive families. As I understand (from reading The Blank Slate), traits come out about what you’d expect if genetics had a strong role in personality: identical twins have very similar personalities even when they’ve been adopted into two different families, often resembling one another more than they resemble their adopted siblings. Fraternal twins show the same personality similarities to one anothe when adopted out that siblings show.

I wish I had a copy of The Blank Slate so I could quote the relevant passage.

Daniel

#12

Of course it can. One explanation is that our genes code for the construction of a brain that can acquire new information, evaluate its importance to survival, and act on that information. The genome need not change to explain one’s change in actions, attitudes, and beliefs.

One distinction that you want to get straight fairly soon is between behavioral genetics and evolutionary psychology. Behavioral genetics just looks at certain behaviors to find whether they are heritable. And if you’re out to disprove behavioral genetics, you’ve got a very hard row to hoe since there are many twin studies out there that provide damning evidence that many human behaviors strongly correlate with heredity.

Science knew a great deal about heredity before anyone actually knew what a gene was, so demonstrating this link with confidence doesn’t actually require that a gene be found. If certain behaviors correlate with heredity, controlling for other factors, then we know there’s a genetic basis since genes are the basis for heredity.

Strawman. It doesn’t. You can make a number of accusations against evolutionary psychology, and I’ll agree with some of them, but nowhere does it say that genes can do anything. It merely follows behavioral genetics in saying that genes can do more than we thought.

The whole proof doesn’t rely on human universals… you can dispute them, but it really doesn’t get you very far.

So, in short… yes, sometimes there’s more heat than light in this very new field of evolutionary psychology… but it’s based on behavioral genetics, which is pretty sound.

#13

What a load of nonsense. Every feature you mentioned can, and has, been changed by humans by an act of will. Our wills are freakin powerful things (though I don’t believe they’re free in any meaningful sense), and we can change just about every inherited feature we have, whether that feature is a preference for a mate or an eye color.

#14

That is an assumption.

I think we can all agree there is a component that is not genetic (physical and social environment), but you can’t just toss out the genetic component.

It could be that genes determine 80% of our personality, or maybe 10%, who knows.

Genetics certainly sets boundaries around any thinking we do throughout our life. Just because we change our mind about something doesn’t mean that genetics is no longer settinng the boundaries. For example, an autistic person can’t just choose to function in a manner that we call "normal’.

#15

Yeah I know about concordance studies I was just too lazy to dig up a specific cite :smiley: Genetics play a larger role than most people think. Evolutionary psychology is 90% bullshit. It has many valid results, but the reasoning for the results is often misapplied or speculative.

#16

The stuff I’ve read from Pinker seems to have some pretty powerful science behind it, and it labels the speculative stuff clearly. OTOH, I had a psych professor in college who told us she loved EP because you didn’t have to prove anything, you got to be creative. :rolleyes:

Daniel

#17

Stephen J. Gould in The Mismeasure of Man has a great quote on this topic:

“If I were an identical twin and had been separated from my brother at birth and later reunited, I would be financially set for life. I and my twin could make a living hiring out our services to researchers wishing to make a point in the nature v. nurture debate, since we would represent the only real method for distinguishing inherited and learned traits. In fact, fewer than twenty such pairs exist, too few to study for meaningful results.”

The main set of studies of twins separated in early childhood come from Cyril Burt, an English psychologist who had an obsession with proving that the poor were genetically inferior to the rich. In order to do so, he first had to prove that traits such as intelligent, morality, promiscuous behavior, drug use, and so forth were all hereditary. To do so, he used large studies of twins separated at birth. The only problem is that he was making up almost all his data. Unfortunately the fraud was not discovered until late in his life, at which point his work had already had substantial influence on policy in England and on scientific views all over the world.

The other method for studying twins is to look at the appearance of certain traits in pairs of identical twins vs. pairs of fraternal twins. This is based on the assumption that all pairs of twins share the same upbringing, but only identical twins share the same genome. Thus, if identical twins are more similar than fraternal twins, the genes must be the culprit. However, the premises for this type of study are not sound, as psychologist [Lea Winerman has explained](Lea Winerman has explained). For one thing, it simply isn’t true that upbringing is the same for pairs of twins of both types. Identical twinsmay be treated much more alike than fraternal twins. Here’s her article on the topic.

As for comparisons of adopted vs. biological children in the same family, I’d love to see any studies on the topic if they exist. It’s occurred to me before that my aunt and uncle, for instance, did a minor study on the topic when they adopted a little girl from a Korean village. So far, it looks to me like nurture is dominating nature. At least, I don’t think most girls in rural North Korea attend Hannah Montana concerts, wear spangled headbands, and play softball. I could be wrong, of course.

#18

So, do you actually argue that genes don’t affect behaviour at all? Do you really think that the fact that most healthy males become sexually aroused by the sight of a naked woman performing sexually suggestive acts doesn’t have anything to do with a genetic incentive to procreate? And where does instinctive behaviour in animals come from, or is that something else because we’re humans and special?

#19

Incredible.

Please learn what a straw man is before continuing with these tedious OPs.

#20

The only thing I got from being raised white, anglo saxon, protestant american girl in the 60s and 70s is a hearty hatred of pink, pastels, ruffles, dresses and lace in varying combinations. I also detest soap operas, celebrity magazines, and wine coolers …
I guess I sort of need to turn in my ovaries, I fail miserable at being girly …