Senior Seminar in Neural and Behavioral Sciences
Bryn Mawr and Haverford Colleges, Spring, 2002
Session 1: Motivations
Discussion
(Readings and Web Links)
Nature or Nurture? There is interplay between both nature and nurture in learning and studying human behavior. I think genetic and evolutionary considerations are both useful and dangerous for thinking about human behavior. Behavioral genetics and evolutionary psychology are different in that behavioral genetics looks at the role of genetic influences as contributors to individual differences, rather than on their role in accounting for shared species characteristics. Behavioral genetics looks for genetic explanations of behavioral traits. However, there are ethical, legal, and social implications of behavioral genetics.
Information about genes I think will influence the practice of medicine and psychiatry in the prevention and treatment of many disorders. Genes partially contribute to variations in behavior among people and to complex behavioral disorders. But it is also shown that environmental influences can initiate changes in gene expression. We have to be careful not to jump to any conclusions and remain optimistic. As specific genes are identified, we can explore how these interact with environmental factors in development.
I look at human behavior as the exercise of free will. Individuals have control over their behavior, their behavior is not determined by biology alone. Why do individuals change on average between two ages? However, there are some human behaviors that cannot be explained causally. Chance events do happen that are beyond our own control.
In genetic/evolutionary considerations, people fear what they do not know or what sounds too complicated. Therefore, it is important to try and make concise explanations and what is being done and be as clear as possible. The book review, And the Blood Cried Out I found interesting because I worked with Harlan Levy's wife during the summer. Unfortunately, scientific evidence used in court many times goes above all parties involved, opposing counsel, judge, and the jury. Therefore, it can make deciding a case difficult. One should also not look at complicated evidence as being correct/incorrect without further proof and clarification.
Many more observations and information is needed to clear uncertainties, but as we advance and build upon past ideas, understanding human behavior might be made clearer. Both genetics and evolution can be used in exploring human behavior.
I think an important question, though, is whether or not the expansion of scientific knowledge is inherently sufficient to justify the clearly intricate and dangerous new problems raised by applications of evolutionary theory and, in particular, genetics. To briefly mention a few of these, I think genetic explanations for behavior clearly raise the specter of eugenics (do we really want to selectively breed our population for behavioral/ other traits? ),; they could lead to enormous levels of discrimination in hiring practice, insurance, education, and any other number of fields; and, more subtly, people are likely to interpret information that a behavior has a genetic basis as indicating that that behavior is uncontrollable, which in most cases is clearly incorrect. There seems to be a knowledge (good) versus applications (bad) dichotomy in my thinking about these fields; my thoughts on the topic are much more complex than I can say in this posting. In fact I actually think that regardless of whether they are 'good' or 'bad,' both the acquisition of new knowledge about the genetic/ evolutionary basis of behavior and the application of that knowledge is going to continue to increase at an extremely rapid pace, regardless of any kind of legislative attempt to control it, in this country or elsewhere. Where does that leave us? Hmm….
To me it seems that papers and magazines such as Time are the ones responsible for propagating this deterministic view. When researchers find significant results for study looking into a gene that is associated with memory, these papers try to make a headline by claiming that scientists have found the smart gene. The general public that reads these publications does not necessarily know any better and begins to buy into the deterministic ideas.
I almost worry that people begin to use these genetic predispositions to traits such as alcoholism or aggression as excuses for their behavior. If I convince myself that I have a problem with aggression because of my genes it will be almost impossible then to convince myself that I can get over this problem and become a healthy, functioning member of society. I think that we can get over these predispositions. Alcoholics can go to AA meetings and talk about how they have been sober for years. What does it mean for the brain to be able to convince the body that it does not need the alcohol? Is this really what’s going on? These questions may be more clear-cut than I seem to think but I don’t know…
I've heard criticisms of evolutionary theory that say that things that happened many thousands of years ago, while they might help explain very general human tendencies, cannot account for the intricacies of all our current behaviors. I think one of the big things that leaves evolutionary explanations less than satisfying to many people is how they treat the human race as a single behavioral unit or as very large groups (e.g. males vs. females), not paying much attention to variations within these groups, and in particular ignoring the notion of free will. That's where perhaps the greatest danger lies in evolutionary/genetic explanations. Is it possible that domestic abuse will be justified on the grounds that there is an evolutionary reason for males to behave violently when they think they've been cuckolded? Or will XYY men be acquitted of crimes because they are "preprogrammed" to be violent? Hopefully not...the scientific community and the public press need to be careful to stress that these are general tendencies, and as autonomous beings we can control our own behavior. But then, if brain=behavior, are we really autonomous at all? hmmm...
Still, evolutionary explanations for human behavior are somehow very appealing to me, particularly when I think about why people engage in seemingly destructive or maladaptive behaviors, or just whenever I don't understand why we do some of the things we do. Rather than putting limits on evolution's and genetics' explanatory power or drawing boundaries around their territory, it seems that they can contribute to our understanding of almost any behavior; they just need to be considered in conjunction with other theories.
Although I think that Cosmides and Tooby’s work is advantageous in that it can help us understand our behavior and our history, I believe that behavioral genetics enters a more serious/dangerous realm. When I read Rothstein’s article in which he warns of the “grievous social consequences” associated of behavioral genetics, I thought he was being a bit dramatic. I gave our society more credit than to think it would revert to eugenics arguments reminiscent of those surrounding The Bell Curve. However, in reading Berkowitz’s accumulation of quotes from modern scientists (some associated with the Human Genome Project), I was shocked to see the common thread of genetic determinism woven into their arguments. I believe it is irrelevant/ridiculous to say that alcoholism, mental illness, homosexuality, intelligence, or various personality traits can be localized to a single gene. I do believe that there is a genetic component to the above- mentioned traits, however, as McInerney stated, “…genes can do nothing by themselves.” It would be a nightmare to see genetics arguments work themselves into public policies, laws, and social hierarchies. However, it seems that behavioral geneticists are a long way from finding substantial, significant, irrefutable results that show causal relationships between genes and behavior. Until then, we should brace ourselves for the myriad of unreliable studies that will be published and watch as they make it to the mainstream media and grace the cover of Time magazine with titles such as, “Gene for Shyness Found!”
What if technology allows us to replace the undesirable genes in the zygote so that the aggression gene is no longer present in the individual? Can nurture alone cause aggression in this person?
Genetics also play an important role in human behavior and therefore it is both necessary and useful to study genetics when looking at human behavior. However, I think that genes do not determine behavior nor do they dictate a particular course that an individual must follow. Rather, I agree with the de Waal article that states, “genes, by themselves, are like seeds dropped onto the pavement: powerless to produce anything.” In other words, the environment in which genes exist also plays a crucial role in determining behavior. I also think that there are certain advantages to studying the role of genetics in human behavior. For example, scientists may discover genes that predispose someone to develop a particular mental disorder, so we can then provide a person with that gene an environment that helps prevent that particular mental illness from arising.
Although I think it is important to consider the genetic and evolutionary contributions to human behavior, I think that one should approach these areas cautiously. Several of the articles raised the issue of the misrepresentation to the public by the media and the misinterpretation by the public of scientific findings related to genes. It seems that scientific findings are sometimes presented incorrectly by the media in order to make a story more appealing and to improve ratings. For example, it may be stated that a gene was found that causes a particular behavioral trait, although it is more likely that the gene predisposes a person to developing that trait and that the environment in which the person resides helps determine if that trait will be expressed or not. This type of misunderstanding by the public can be dangerous (consider the examples pertaining to law that Rothstein discussed and some people’s intolerance of people with abnormal conditions), so it is important that when scientists conduct this type of research they also help present the information correctly to the public and help correct any misunderstandings held by the public.
I am fairly certain that genetic and environmental factors both affect human behavior, but I am uncertain of the extent to which these effects occur. Further exploration of the topic throughout the semester and by scientists in the field should hopefully lead us to an even better understanding of this complex issue.
It was great to read a psychology article that actually talked about the importance of biology and evolution of all things in studying the mind. Having just taken an Evolution class, where I wrote my final paper on the evolution of the brain in primates I thought it was great stuff. I think evolutionary considerations are hugely necessary and useful in thinking about human behavior. People often fall into this trap of thinking that society and humans come out of no where. Saying that, oh behavior doesn't come from the brain it comes from society. But where did that society come from itself? It didn't arise out of nothing, and what we are determines who we are.
I also think the discussion of instincts having a much greater say in our minds than we previously thought clears up a lot of things. The notion of 'assocation cortex' certainly did seem to be a cop out way of describing the neocortex because they couldn't pinpoint exactly what it did. I think the EP author went a little too far with his stress on the egalitarianism of evolutionary psychology. Just because not all people have the same ability according to the integration of nature/nurture theory, does not serve to discredit it. In fact, I think it goes pretty far to explain a lot. Even though all humans are very genetically similar, our morphology makes it evident that slight changes can result in significant differences. Changes in hardwiring explain how even siblings brought up in the same environment may excel in very different fields.
Studying human behavior from an evolutionary standpoint give a lot of insight into the creation of our brain's structure and what impact that had on behavior. Archeaologists can determine some typical behaviors for our human ancestors, at the same time changes in the size of different brain areas can be seen. This study also allows us to look at the way our behavior evolved and its true purpose. Behaviors that seem problematic today (ie, aggression, promiscuity) may have evolutionary benefits to be looked at.
Evolution is not an exact science either, however. And even if we gain a greater understanding of how consciousness developed, we still may not come any closer to understanding how consciousness works. Looking at humans (or any species group) as homogenous is a large fallacy in biology that needs to be corrected I think. Instead, gene populations would better be studied as the true units of evolutionary change.
One particular example would be in the de Waal (I've read other things he's done) article where he talks about how some evidences for the phenomenon of incest and "early familiarity". He talks about a great example of testing this is a study where they found a culture in Taiwan that had spouses who were raised with eachother. This was compared to a culture where people don't meet till the wedding day. Well, the confounds in this example are extraordinary. When you compare divorce and fertility rates as examples for marital happiness and sexual activity... well, I bet that cultures that are so different in marital relations probably have different views about divorce. I bet divorce occurs less in such family-strong cultures like asia as it would in western cultures where we meet potential spouses in our maturity. There just seems to be such huge openings for confounds. This is just one example, but it is important to realize that we are combining something so exact (protien synthesis receipes) to phenomenon that use a much less technical language. All of these articles remind me of Learning theory and Behavior topics. Several of us are in this class.
Similarly, though all this talking about genetics and cultural differences is interesting, the phenomenon of biased tests was only mentioned once and that was veild and in passing. We learned in Cog. Psych that there are bias tests, not just genes. I think this holds some influence in deciding how we interact with the genetic findings. I think that's very important.
I did find it interesting though when they talked about how protiens are needed to express the patterns and instructions in the genetic material. I think this was an insightful way to look at it, and realize that this is also similar to our use of dopamine/seratonin (etc.) manipulating drugs rather than gene-therapy (heretofor impossible). Though would we eventually go that far?
1 - There seemed to be consensus that both genetics and evolution ARE useful additions to other ways of exploring/trying to better understand human behavior. I was particularly intrigued by the idea that some aspects of human behavior seem "irrational" (is that really what we mean? would "hard to understand" be better?) EXCEPT in the context of evolution. And no one seemed to doubt the evidence that genes CAN influence behavior, as long as it was clearly understood that genes are an INFLUENCE, not a DETERMINANT.
2 - With regard to evolution, there was, it seems to me, a useful distinction made between generating hypotheses to explore about the causes of human behavior based on considerations of evolution, and accepting that particular evolutionary ideas explained behavior. There are two issues here. One is that one can't "go back" and test evolutionary explanations by directly checking them. If evolutionary thinking is to be used, one has to phrase hypotheses based on it in ways that can be tested (potentially falsified) by observations it is currently possible to make (a similar concern about evolutionary "explanation" arises in other biological contexts, as exemplified by Stephen J. Gould's concerns about "just so stories"). The other issue is to bear in mind that evolution (like genes, which are presumably the intermediary in its influences) are an INFLUENCE, not a DETERMINANT.
3 - I think we need to do some more talking about the "influence" versus "determinant" idea. As discussed, this seems to be a continuum with some genetic (evolutionary?) factors closer to the "determinant" side (sickle cell anemia, PKU problems and mental retardation, schizophrenia?). On the other hand, it was usefully pointed out that even in the more extreme cases, environmental and/or self-induced activities can affect outcomes (as in diet for PKU problems, use of neuropharmacological agents, etc).
4 - I think we also need to do some more talking about whether it is appropriate to talk about a gene for X (eg an "alcoholism") gene. The issues here have to do with "influence" versus "determinant" (as above) but also with how MANY genes are likely to be involved in (influence) any behavior, the likelihood that a given gene influences many behaviors, and the dependence of the influence of a given gene on other genes.
5 - There are clearly significant public policy matters for which the above considerations are relevant. One set of concerns is the extent to which genetic/evolutionary considerations in fact threaten concepts of "free will" and "personal choice". The consensus in the group seemed to be that they don't, because they are influences rather than determinants. This seems worth further discussion, since it is hard at the moment to specify what is meant by "free will" and "personal choice" with enough precision to evaluate whether they might in fact be affected by genes (could particular genes diminish the extent of "free will"? might the extent of "free will" be itself a product of evolution?).
6 - A second set of concerns in the public policy arena is the extent to which genetic/evolutionary explorations might diminish a belief in "free will" and/or "personal choice" in people who are less familiar with the scientific literature. If this is of concern, the issues are what should be done about it, and by whom? Is it a media problem, a science problem? How can one assure broader understanding? On the other hand, an interesting argument was made that people in general may be more sophisticated in this area than many scientists, having in their day to day life abundant experience with genes as an "influence" rather than a "determinant" (people from families with histories of alcohol abuse who act not to continue it).
7 - A third set of concerns in the public policy arena has to do with the potential for discrimination against people based on information about their genetic background. It is, perhaps, in this area that it is most important to assure public awareness of the "influence not determinant" idea. There may also be a need for greater public awareness of the more general biological idea that "normal" is not a well-founded idea, and that "diversity" is itself desirable.
8 - A fourth set of concerns in the public policy arena is, in some ways, the opposite of the concern about diminished "personal choice": with increasing information about genetic influences, people may acquire greater opportunities for personal choice in regard to, for example, choosing characteristics of their offspring. Should this be thought of as "discrimination" or simply as a further enhancement of long-standing practices of individual human beings to influence gene pools (via mate selection, elective abortion, etc)? Are there compelling social issues requiring collective policy decisions or should choices of this kind be left to individuals? Are some situations of the former and some of the latter kind and, if so, what's the basis for such distinctions?
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