# Evolutionary Cognitive Neuroscience: The Revenge
**URL:** https://boards.straightdope.com/t/evolutionary-cognitive-neuroscience-the-revenge/486635
**Category:** Great Debates
**Created:** [February 19, 2009, 11:59pm UTC](https://boards.straightdope.com/t/evolutionary-cognitive-neuroscience-the-revenge/486635 "2009-02-19T23:59:24Z")
**Posts on this page:** 20
**Page:** 2
### Author:  [@HMS\_Irruncible](https://boards.straightdope.com/u/HMS_Irruncible)
#### Post date: [February 20, 2009, 6:56pm UTC](https://boards.straightdope.com/t/evolutionary-cognitive-neuroscience-the-revenge/486635/21 "2009-02-20T18:56:58Z")
> [@ITR\_champion](#):
>
> "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.
This piece of rhetoric is easily proven. There are a number of identical twins separated from birth. Are any of them financially set for life due to this fact? If you can demonstrate that, then this bit of fluff gains some substance; otherwise it’s just an empty polemic.
> [@](#):
>
> The main set of studies of twins separated in early childhood come from Cyril Burt,
“Early” does not mean the same thing as “main”. There are numerous other studies.
> [@](#):
>
> …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.
Bit of a poisoned-well fallacy here, don’t you think?
> [@](#):
>
> 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).
The oblique appeal to authority falls flat here, since Lea Winerman is a journalist, not a psychologist. Not the last of the problem, however…
> [@](#):
>
> For one thing, it simply isn’t true that upbringing is the same for pairs of twins of both types. Identical twin smay be treated much more alike than fraternal twins. [Here’s her article on the topic.](http://www.apa.org/monitor/apr04/second.html)
The article deals with problematic interpretations that crop up sometimes with twin data. It also deals with ways that these are being improved. Even the critical source in the article says that some of the problem assumptions aren’t as important as one thought.
> [@](#):
>
> 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.
What relevance could such a study have even in the most ideal world? It would be impossible to rule out that the parents treat the children differently, unless they were foster parents who didn’t know that one child was adopted.
Have you read any good books on the subject, say some of Steven Pinker’s work?
---
### Author:  [@Bryan\_Ekers](https://boards.straightdope.com/u/Bryan_Ekers)
#### Post date: [February 20, 2009, 7:01pm UTC](https://boards.straightdope.com/t/evolutionary-cognitive-neuroscience-the-revenge/486635/22 "2009-02-20T19:01:46Z")
Haven’t read the thread in any great detail (will do so later on), but does evolutionary psychology _have_ to be genetic? Consider this:
[ul][li]Much of our individual viewpoints and responses are shaped by the society in which we are raised.[/li][li]These societies themselves represent organic processes: they gradually and slowly evolve, albeit at a pace much faster than _homo sapiens_ itself.[/li][li]The various human societes are themselves competitive and prone to environmental pressures. Native American societies were devasated when European germs were introduced, for example. Even now, some societies are dying out because of assimilation by other, more successful societies.[/ul][/li]In short, psychology is an evolutionary process, it’s just not necessarily a _genetic_ evolutionary process. The attitudes of an American in 2009 are likely to be different in several significant ways from an American in 1809, but this is clearly not an evolution of humanity, but just of American culture itself - picking up new traits (suffrage, equality, technology) while discarding useless ones (slavery, biblical literalism, aristocracy) though appendix-like vestiges remain.
---
### Author:  [@ITR\_champion](https://boards.straightdope.com/u/ITR_champion)
#### Post date: [February 20, 2009, 7:41pm UTC](https://boards.straightdope.com/t/evolutionary-cognitive-neuroscience-the-revenge/486635/23 "2009-02-20T19:41:06Z")
> [@Left\_Hand\_of\_Dorkness](#):
>
> [What](http://www.allaboutvision.com/contacts/colors.htm) [a](http://www.clairol.com/products/products.jsp) [load](http://www.guardian.co.uk/world/2003/dec/15/gender.uk) [of](http://www.plasticsurgery.org/Patients_and_Consumers/Procedures/Cosmetic_Procedures/Nose_Surgery_for_Women.html) [nonsense](http://www.gla.ac.uk/departments/philosophy/Personnel/susan/WebpagesSCATS06-07/DuncanGrahamIain/voluntary_amputation.html). Every feature you mentioned can, and has, been changed by humans by an act of will.
To state the bleedingly obvious, I meant that eye color, hair color, and all the rest cannot be changed merely by mental effort. They can be changed by physical means, but that’s irrelevant to this discussion.
---
### Author:  [@DSeid](https://boards.straightdope.com/u/DSeid)
#### Post date: [February 20, 2009, 7:41pm UTC](https://boards.straightdope.com/t/evolutionary-cognitive-neuroscience-the-revenge/486635/24 "2009-02-20T19:41:35Z")
Let’s try to separate out a few different topics that have been combined together here, shall we.
**Nature v Nurture.**
Part A. Twin Studies.
Twin studies are not restrict to nor primarily identical twins raised apart. They generally consist of comparing concordance rate for a particular trait between identical and fraternal twins. The degree to which identical twins share a trait substantially more than do fraternal twins (who equally shared environmental factors) quantifies how much specific genes play a role in the trait. Such studies show elements of heritability for many behavioral traits, including [prosocial behaviors,](http://www.ncbi.nlm.nih.gov/pubmed/16953685?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DiscoveryPanel.Pubmed_Discovery_RA&linkpos=1&log$=relatedarticles&logdbfrom=pubmed) [anxiety/depression,](http://www.ncbi.nlm.nih.gov/pubmed/16268991?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DiscoveryPanel.Pubmed_Discovery_RA&linkpos=3&log$=relatedarticles&logdbfrom=pubmed) [pathologic gambling,](http://www.ncbi.nlm.nih.gov/pubmed/19210181?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum), [eating rate,](http://www.ncbi.nlm.nih.gov/pubmed/19064516?ordinalpos=7&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum) [substance abuse,](http://www.ncbi.nlm.nih.gov/pubmed/17539362?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DiscoveryPanel.Pubmed_Discovery_RA&linkpos=1&log$=relatedarticles&logdbfrom=pubmed) and many others. As for the critique that identical twins may be treated more alike than fraternal twins … yeah, and so? Why? Because of the the way they look and the way they behave/react differently than a twin with a different genome? Uh yeah. Influencing how someone responds to and is responded to by the environment including others is one mechanism of how genes effect behavioral outcomes.
```
Part B. Individual Genes.
```
Of course the genome influences behavior in concert with the environment and by way of multiple genes and epigenetic factors. A gene may be associated with advantages if coupled with another gene or disadvantages when coupled with different ones, be beneficial in one environment or for one task and detrimental in a nother or with another task. So having an exact and reproducible, easily pegged gene-behavior concordance? Doubtful. Having effects that could be the fodder for selection? No doubt.
You may want to get your hands on [this Nov.'08 Science article.](http://www.sciencemag.org/cgi/content/summary/sci;322/5903/892?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=parsing+genetics+behavior&searchid=1&FIRSTINDEX=0&resourcetype=HWCIT) The full article is behind the wall but I’ll quote some pertinent parts.
> [@](#):
>
> That genes strongly influence how we act is beyond question. Several decades of twin, family, and adoption studies have demonstrated that roughly half of the variation in most behavioral traits can be chalked up to genetics. But identifying the causal chain in single-gene disorders such as Huntington’s disease is child’s play compared with the challenges of tracking genes contributing to, say, verbal fluency, outgoingness, or spiritual leanings … All we really know so far is that behavioral genes are not solo players; it takes many to orchestrate each trait. Complicating matters further, any single gene may play a role in several seemingly disparate functions. For example, the same gene may influence propensities toward depression, overeating, and impulsive behavior, making it difficult to tease out underlying mechanisms.
>
> Each gene comes in a variety of flavors, or alleles, with varying degrees of sequence variation. One allele might contribute to a winning personality whereas another may raise the risk of mental illness. Environment plays a strong hand, bringing out, neutralizing, or even negating a gene’s influence. And genes interact with one another in unpredictable ways. …
>
> … A team led by Hasse Walum of the Karolinska Institute in Stockholm looked at the DNA preceding the AVPR1a gene in about 500 pairs of adult same-sex Swedish twins, all of them married or cohabiting for at least 5 years, and their partners. One short variant of a stretch of DNA in this region–there are several variants–was associated with less stable relationships. Answers to questions such as “How often do you kiss your mate?” and “How often are you and your partner involved in common interests outside the family?” reflected slightly lower feelings of attachment on the part of men with this variant, researchers reported in the 16 September issue of the Proceedings of the National Academy of Sciences. These men were less likely to be married and, among those in relationships, more likely to have experienced recent marital strife. … Another paper published last spring showed a different link between AVPR1a and how people treat others. Richard Ebstein and colleagues at Hebrew University in Jerusalem reported that the length of the variant predicted how human subjects would respond in the “dictator game,” a way to assess altruism. The researchers divided 200 volunteers into groups “A” and “B.” The “A’s” received $14 each and were told to share as much as they wished with a “B” whom they had never met. About 18% kept all the money, and 6% gave it all away, with the rest somewhere in the middle. The people who behaved more selfishly–or, as the headlines proclaimed, more ruthlessly–had the same variant as the people with the less stable relationships in the study mentioned earlier. Ebstein speculates that in these people, vasopressin receptors were distributed in such a way that they provided less of a sense of reward from the act of giving (or loving)…
>
> … resilience may lie in a gene for a protein that regulates serotonin, a brain messenger that has been associated with emotional ups and downs. The gene is called SERT for serotonin transporter.
>
> In a classic paper published in Science in 1996, Klaus-Peter Lesch of the University of Würzburg, Germany, and colleagues at the U.S. National Institutes of Health reported that the length of the regulatory DNA at the beginning of SERT affected human behavior. Lesch’s team found that among 505 adults, those scoring high on various tests measuring “neuroticism”–depression and anxiety–tended to have one or two copies of a short variant whereas those who were more laid back had only the long form. The short version translates into more serotonin in the synapse, and too much serotonin leads to anxiety, in both animals and humans…
>
> … the effect of the gene depends on life experiences. In Dunedin, New Zealand, researchers led by Avshalom Caspi of the Institute of Psychiatry in London tracked 847 people over more than 20 years from the age of 3. The researchers counted stressful life events occurring between the ages of 21 and 26 and asked subjects if they had been depressed in the past year.
>
> Among people who had not reported any major life stresses, the probability of depression was low regardless of their SERT alleles. But among people who had been through four or more stressful experiences, 43% of those with two short alleles reported a major depressive episode–more than double the proportion of subjects with two long alleles. The study also showed that almost two-thirds of people with a history of abuse as children experienced major depression as adults if they had two short alleles. But child abuse didn’t raise the risk of adult depression in people with two long alleles…
>
> … they’ve been trying to nail down the role of dopamine receptors, in particular one called the D2 dopamine receptor, in addictions to alcohol, drugs, smoking, or gambling, as well as eating disorders and obesity. … in a group of 195 student subjects at Binghamton University in New York state, those with A1 alleles were more likely to engage in early sexual activity but were less inclined to develop steady relationships… people with two A2 alleles (and no A1) were 8% more likely to form political attachments. Fowler called it “the first gene ever associated with partisan attachment.”… boys with one A1 allele tended to have higher delinquency rates than those with two copies of the A2 allele. But the rates were also higher than in those boys with two A1 copies, suggesting that there is not a simple relationship between the amount of dopamine and behavior…
>
> … the gene for catechol O-methyltransferase (COMT), an enzyme that breaks down dopamine in the prefrontal cortex, the seat of higher cognitive functions such as planning and reasoning. … 497 undergraduates personality tests and found that those with low-activity COMT genes were more neurotic and less extraverted. … a difference in a simple test that has come to be recognized as a reliable indicator for anxiety: the startle reflex, as manifested in involuntary eye blinking in response to a sudden noise or unpleasant pictures. Among 96 female psychology students, individuals with two copies of the low-activity COMT had the most exaggerated startle responses … Yet other work evaluating how well individuals organize their thoughts found low-activity COMT to be an asset. Psychiatrist Daniel Weinberger and colleagues at NIMH think they know why. Brain-imaging studies of 100 normal adults found that those with the low-activity COMT have denser nerve connections. Weinberger and others speculate that the elevated dopamine in the prefrontal cortex may bolster temporary connections, leading to better concentration but reduced ability to shift focus and more behavioral rigidity. As a result, a person may dwell excessively on stressful thoughts. So the gene seems to come with a tradeoff–better cognitive function but more anxiety–the scientists conclude. …
Our genomes give us some particular tendencies (that may be hard to exactly describe); how they are expressed is a function of the environment.
**Evolutionary Biology.**
```
A fine way of organizing thinking and of using evolutionary concepts to help understand how behavioral tendencies might come to be but it is hard-pressed to make very many falsifiable claims. It's sort of like the String Theory of biology.
```
---
### Author:  [@ITR\_champion](https://boards.straightdope.com/u/ITR_champion)
#### Post date: [February 20, 2009, 7:46pm UTC](https://boards.straightdope.com/t/evolutionary-cognitive-neuroscience-the-revenge/486635/25 "2009-02-20T19:46:35Z")
> [@Mangetout](#):
>
> Why does something that evolved need to be universal? - evolution typically produces _diversity_, in the big picture.
Beats the heck out of me. In my first thread on evolutionary psychology, many posters responded to me by saying that the existence of human universals proved the basis of evolutionary psychology. Now that I’ve investigated the basis of these “human universals”, it seems no one wants to defend that line of reasoning any longer.
---
### Author:  [@DSeid](https://boards.straightdope.com/u/DSeid)
#### Post date: [February 20, 2009, 8:20pm UTC](https://boards.straightdope.com/t/evolutionary-cognitive-neuroscience-the-revenge/486635/26 "2009-02-20T20:20:53Z")
Upon reread of my post - that should have been “Evolutionary _Psychology_” obviously. My apologies an having missed that.
---
### Author:  [@ITR\_champion](https://boards.straightdope.com/u/ITR_champion)
#### Post date: [February 20, 2009, 8:23pm UTC](https://boards.straightdope.com/t/evolutionary-cognitive-neuroscience-the-revenge/486635/27 "2009-02-20T20:23:25Z")
> [@brazil84](#):
>
> 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.
Actually it does not. Take the issue of fatty foods. The standard explanation from evolutionary psychology goes like this. Back during caveman times, it was healthy to eat lots of fatty food. As a result, we evolved genes which make us desire fatty foods. Fast forward to modern times, and fat-packed foods are everywhere. Unfortunately our caveman genes still force us to desire fatty foods, hence the prevalence of obesity.
There are problems with this explanation. First of all, we have no gene encoding a desire for fatty foods. We have taste buds on our tongue that produce certain sensations in response to certain tastes, such as sweet, bitter, etc… I suppose some of these categories appear in foods that contain a lot of fat, but there’s nothing pleasurable about fat as fat. Most people would agree that chewing a piece of pure fat is disgusting. (The again, some would disagree.)
In any case, there’s no reason to believe that the flavors we like today are the same ones that our caveman genes were selected to like. Today many of us would enjoy a fattening plate of fettucini alfredo, but there was no fettucini alfredo among the Neanderthals, nor anything that tasted like it. I doubt that roast mammoth haunch tastes much like fettucini alfredo (or french fries or country-fried chicken). In fact we don’t know very much about what our caveman ancestors ate. Bones at a few sites suggest a diet of meat, but we have can’t know any more than that. So the entire explanation for diet is based on far-fetched speculation and not supported by solid facts.
---
### Author:  [@HMS\_Irruncible](https://boards.straightdope.com/u/HMS_Irruncible)
#### Post date: [February 20, 2009, 8:27pm UTC](https://boards.straightdope.com/t/evolutionary-cognitive-neuroscience-the-revenge/486635/28 "2009-02-20T20:27:18Z")
> [@ITR\_champion](#):
>
> Beats the heck out of me. In my first thread on evolutionary psychology, many posters responded to me by saying that the existence of human universals proved the basis of evolutionary psychology. Now that I’ve investigated the basis of these “human universals”, it seems no one wants to defend that line of reasoning any longer.
Your investigation consists of:
1. A non-science blogger quoting a non-science blogger saying “I am a believer in Evolutionary Psychology”.
2. A color preference study that doesn’t claim to prove a human universal
3. A lame dismissal of Brown’s list of universals (you can go get [the book](http://boards.straightdope.com/sdmb/newreply.php?do=newreply&p=10854011) if you’re really interested in learning about it. It’s an ethnographical and historical analysis of traits that have been observed in every culture that has been studied in a non-trivial way.
As to Brown’s list of human universals, his position was to debunk the concept of cultural relativism. The reason it is significant from the position of evolutionary psychology is that it raises the question… if unrelated cultures halfway across the world both share this trait, how did it get to be that way? We don’t have anything in common except sharing human DNA, so it’s a strong possibility that we can thank genes for producing minds that can give rise to these universals. We already know that genes can influence certain cognitive phenomena, FOXP2 and language for example, so these proposed universals give us other things to investigate for the same sort of convergence.
---
### Author:  [@HMS\_Irruncible](https://boards.straightdope.com/u/HMS_Irruncible)
#### Post date: [February 20, 2009, 8:35pm UTC](https://boards.straightdope.com/t/evolutionary-cognitive-neuroscience-the-revenge/486635/29 "2009-02-20T20:35:09Z")
> [@ITR\_champion](#):
>
> Actually it does not. Take the issue of fatty foods. The standard explanation from evolutionary psychology goes like this. Back during caveman times, it was healthy to eat lots of fatty food. As a result, we evolved genes which make us desire fatty foods. Fast forward to modern times, and fat-packed foods are everywhere. Unfortunately our caveman genes still force us to desire fatty foods, hence the prevalence of obesity.
>
> There are problems with this explanation. First of all, we have no gene encoding a desire for fatty foods.
Actually, there’s [CD36](http://www.sciam.com/article.cfm?id=potential-taste-receptor), which codes for a taste but receptor that has been associated with fat tasting and digestion. Receptors are proteins. And as you keep pointing out, DNA codes for proteins.
---
### Author:  [@DSeid](https://boards.straightdope.com/u/DSeid)
#### Post date: [February 20, 2009, 8:56pm UTC](https://boards.straightdope.com/t/evolutionary-cognitive-neuroscience-the-revenge/486635/30 "2009-02-20T20:56:06Z")
I realize that my post was a bit wordy so allow me to pare it down:[ol]
[li]We know that there are genes that effect behavior in both direct and indirect ways.[/li][li]We know that differences in behavior can effect survival and reproductive success.[/li][li]Any genetic variation that effects survival and reproductive success will be selected for or against.[/li][li]Therefore the basic tenent of evolutionary psychology is sound; specific hypotheses may be speculative at this time however.[/li][/ol]
---
### Author:  [@Left\_Hand\_of\_Dorkness](https://boards.straightdope.com/u/Left_Hand_of_Dorkness)
#### Post date: [February 20, 2009, 9:50pm UTC](https://boards.straightdope.com/t/evolutionary-cognitive-neuroscience-the-revenge/486635/31 "2009-02-20T21:50:13Z")
> [@ITR\_champion](#):
>
> To state the bleedingly obvious, I meant that eye color, hair color, and all the rest cannot be changed merely by mental effort. They can be changed by physical means, but that’s irrelevant to this discussion.
To state the bleeding obvious, every single physical means I mentioned above follows mental effort. Hair dye doesn’t fall from the sky like rain. You don’t wake up in the morning with tinted contacts. Leg lengthening procedures aren’t the result of a virus. Conversely, emotional attachments aren’t merely mental effort: you have to take such physical actions as talking to someone, engaging in appropriate body language, etc. in order to strengthen those attachments.
We humans are quite adept at taking our genetic hand and altering it according to our will.
YOur other post to me has already been shredded, so I won’t stomp on its remains.
Daniel
---
### Author:  [@ITR\_champion](https://boards.straightdope.com/u/ITR_champion)
#### Post date: [February 20, 2009, 10:22pm UTC](https://boards.straightdope.com/t/evolutionary-cognitive-neuroscience-the-revenge/486635/32 "2009-02-20T22:22:05Z")
> [@DSeid](#):
>
> Part B. Individual Genes.
> Of course the genome influences behavior in concert with the environment and by way of multiple genes and epigenetic factors. A gene may be associated with advantages if coupled with another gene or disadvantages when coupled with different ones, be beneficial in one environment or for one task and detrimental in a nother or with another task. So having an exact and reproducible, easily pegged gene-behavior concordance? Doubtful. Having effects that could be the fodder for selection? No doubt.
>
> You may want to get your hands on [this Nov.'08 Science article.](http://www.sciencemag.org/cgi/content/summary/sci;322/5903/892?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=parsing+genetics+behavior&searchid=1&FIRSTINDEX=0&resourcetype=HWCIT) The full article is behind the wall but I’ll quote some pertinent parts.
> Our genomes give us some particular tendencies (that may be hard to exactly describe); how they are expressed is a function of the environment.
I’ve encountered a number of sources that are skeptical about some of the results mentioned in that article. For example, [this book](http://human-nature.com/nibbs/03/joseph.html) contains a response to the Caspi study, looking in detail at what the results were on how convincing they are or aren’t.
> [@](#):
>
> An interesting twist to this discussion concerns the recent paper in Science about the discovery that individuals with at least one copy of the short allele of the 5-HTT promoter polymorphism were more susceptible to depression if they were also exposed to a series of traumatic events (Caspi, Sugden, Moffitt et al., 2003). Some researchers have said that this study will aid in identifying people prone to depression even though in the group of clinically depressed patients exposed to four traumatic events 86% of them carried at least one copy of the short allele, or susceptibility gene, while in the group exposed to four traumatic events who did not become depressed, 72% were also carriers of the short allele. It is unclear how this information would aid in identifying who is susceptible to depression or, even more controversial, what type of treatment would be provided. Imagine the interaction between a doctor and a clinically depressed patient who had experienced four traumatic events; it would seem that the most important element in this interaction would be the traumatic events, and not whether the person had the short allele. The person’s genetic makeup is entirely unnecessary for any explanation of the depression and the “genetics” in no way implies that drugs are needed. But most importantly, and not mentioned in many of the newspaper accounts of this study, is that 68% of the population carries at least one copy of this allele. [7]
(The same source also takes a hammer to twin studies: a double whammy.)
The general issue of serotonin and its link to depression gets cited all the time in discussions like this, yet it’s not as settled as some people seem to think. For one thing, there’s been a recent cascade of drugs aiming to treat depression by means of increasing serotonin levels in the brain. Yet reviews of the performance of those drugs in multiple studies seem to be casting doubt on their effectiveness. An interesting point is made by Marcia Angell [in this article.](http://www.nybooks.com/articles/22237) Most people have high confidence in articles written by scientists in this field, but probably do not know where much of the funding for this sort of research is coming from. The pharmaceutical industry provides funding for scientific research in the academic world to the tune of billions of dollars, through a variety of channels. That means that a number of researchers (almost all of them) have a strong motivation to keep the pharmaceutical industry happy. And the industry, needless to say, mainly wants to hear that mental traits have simple, physical causes, because that has to be true for profit to be made. The might cause some researchers, consciously or unconsciously, to tilt their research towards physical explanations.
Anyway, there’s a lot of food for thought here. I’ll try to look into that article when I get the chance.
---
### Author:  [@Discordia](https://boards.straightdope.com/u/Discordia)
#### Post date: [February 20, 2009, 10:37pm UTC](https://boards.straightdope.com/t/evolutionary-cognitive-neuroscience-the-revenge/486635/33 "2009-02-20T22:37:04Z")
> [@ITR\_champion](#):
>
> The general issue of serotonin and its link to depression gets cited all the time in discussions like this, yet it’s not as settled as some people seem to think. For one thing, there’s been a recent cascade of drugs aiming to treat depression by means of increasing serotonin levels in the brain. Yet reviews of the performance of those drugs in multiple studies seem to be casting doubt on their effectiveness.
Why are you citing science [studies](http://boards.straightdope.com/sdmb/showthread.php?t=474129)? You seem to prefer anecdotes, so I’ll offer mine: They work wonderfully for me.
---
### Author:  [@DSeid](https://boards.straightdope.com/u/DSeid)
#### Post date: [February 20, 2009, 10:41pm UTC](https://boards.straightdope.com/t/evolutionary-cognitive-neuroscience-the-revenge/486635/34 "2009-02-20T22:41:52Z")
**ITR** , your sources critique of the gene’s _clinical utility_ (or lack thereof) is immaterial to the issue at hand here: do genes lead to behavioral tendencies and susceptibilities in any statistically significant fashion?
Yes they do. Now the exact pathway and he exact behaviors may be ill-described, and why the same alleles are helpful in one circumstance and harmful in another may be poorly understood; it may be of no clinical utility whatsoever; how the different genes interact with each other and with environmental factors may be not yet completely clear. But it is a documented fact that genes strongly influence behavioral outcomes in humans and that such behaviors would be expected to be fodder for selective pressures.
Honestly to argue the converse, that somehow behavior in humans is absent any genetic influence and immune to selective pressures, is a bit absurd.
---
### Author:  [@Lobohan](https://boards.straightdope.com/u/Lobohan)
#### Post date: [February 20, 2009, 11:32pm UTC](https://boards.straightdope.com/t/evolutionary-cognitive-neuroscience-the-revenge/486635/35 "2009-02-20T23:32:08Z")
> [@DSeid](#):
>
> Honestly to argue the converse, that somehow behavior in humans is absent any genetic influence and immune to selective pressures, is a bit absurd.
Not if you believe in souls like the OP. I’m sure for the sake of his irrational beliefs he’d rather assume that humans are blank slate vehicles that the soul controls.
It’s interesting that the OP is highly critical of a genetic basis for behavior, yet accepts without evidence the existence of god, the supernatural and an afterlife.
It’s amazing that people can compartmentalize their skepticism and only bring it out when it conflicts with something they want to believe.
I wonder if there is a gene for that. 😃
---
### Author:  [@alterego](https://boards.straightdope.com/u/alterego)
#### Post date: [February 21, 2009, 7:53am UTC](https://boards.straightdope.com/t/evolutionary-cognitive-neuroscience-the-revenge/486635/36 "2009-02-21T07:53:17Z")
> [@ITR\_champion](#):
>
> 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.
There is such an overwhelming amount of evidence that our preferences and behaviors have strong genetic components that I’m really not sure what you’re asking me. I gave a clear example of how your genome encodes for sophisticated repertoires of behavior in the previous thread.
---
### Author:  [@Half\_Man\_Half\_Wit](https://boards.straightdope.com/u/Half_Man_Half_Wit)
#### Post date: [February 21, 2009, 12:28pm UTC](https://boards.straightdope.com/t/evolutionary-cognitive-neuroscience-the-revenge/486635/37 "2009-02-21T12:28:34Z")
I’m feeling a little ignored. ☹
Once more, fucking is a human behaviour, it’s a universal, it’s enjoyable to the overwhelming majority of the members of our species, how the hell are we supposed to be still here if there’s not a genetic incentive for this?
And again, where does instinctive behaviour in animals come from?
---
### Author:  [@Half\_Man\_Half\_Wit](https://boards.straightdope.com/u/Half_Man_Half_Wit)
#### Post date: [February 21, 2009, 12:49pm UTC](https://boards.straightdope.com/t/evolutionary-cognitive-neuroscience-the-revenge/486635/38 "2009-02-21T12:49:24Z")
Oh and, by the way, even though most behaviours are likely to be polygenic, a [single gene that affects human bonding behaviour](http://www.medicalnewstoday.com/articles/120395.php) has, in fact, been found.
---
### Author:  [@Left\_Hand\_of\_Dorkness](https://boards.straightdope.com/u/Left_Hand_of_Dorkness)
#### Post date: [February 21, 2009, 1:46pm UTC](https://boards.straightdope.com/t/evolutionary-cognitive-neuroscience-the-revenge/486635/39 "2009-02-21T13:46:52Z")
> [@Half\_Man\_Half\_Wit](#):
>
> I’m feeling a little ignored. ☹
>
> Once more, fucking is a human behaviour, it’s a universal, it’s enjoyable to the overwhelming majority of the members of our species, how the hell are we supposed to be still here if there’s not a genetic incentive for this?
>
> And again, where does instinctive behaviour in animals come from?
There are so many examples like this: hunger, thirst, sociability, language, dominance behavior, imitative play, etc. The idea that we’re blank slates is a really bizarre one.
Daniel
---
### Author:  [@alterego](https://boards.straightdope.com/u/alterego)
#### Post date: [February 21, 2009, 1:51pm UTC](https://boards.straightdope.com/t/evolutionary-cognitive-neuroscience-the-revenge/486635/40 "2009-02-21T13:51:24Z")
As I said in the other thread (but no one replied to…):
**Regarding behavior**
Motor cortex has a somatotopic organization of behaviors. Many people are aware of the [motor cortex topographic homonculus](http://scienceblogs.com/pontiff/400px-Sensory_and_motor_homunculi.jpg) (image) which has areas dedicated specifically to each body part. Neurons are dedicated to each area in proportion to that area’s survival utility. The mouth/hands get a lot of cortex. The pecker is pretty big too. Less well known is that overlayed on this map is _behavioral homunculus_ that follows the same rule. Putting an electrode in monkey motor cortex forces the monkey to perform activities based on the site of stimulation. The longer the stimulation, the more sophisticated the behavior. For example, its trivial to get the monkey to get out of his chair and try to climb, eat or have sex with nothing. This rule obviously follows for humans as well. The development of such representations is of course a gene/environment interaction, but there is no doubt that these behaviors are encoded in your genome. Your genome encodes for your limbs, and the “environment” for motor cortex is the body, which is encoded for by your genome. It only takes movement of the relevant body parts in order for the appropriate representations to develop. This has been demonstrated in research on kittens. They tape the front two legs back for a significant period of time after birth. That area of motor cortex does not develop. They then remove the tape and allow the kitten to learn to walk. Motor cortex develops identically.
[ul]
[li] Graziano (2006). [The organization of behavioral repertoire in motor cortex](http://arjournals.annualreviews.org/doi/abs/10.1146/annurev.neuro.29.051605.112924?cookieSet=1&journalCode=neuro). Annual Review of Neuroscience (msg me for pdf)[/li][/ul]
[Previous page](https://boards.straightdope.com/t/evolutionary-cognitive-neuroscience-the-revenge/486635.md?page=1)
[Next page](https://boards.straightdope.com/t/evolutionary-cognitive-neuroscience-the-revenge/486635.md?page=3)