Re: genetics is gaining ground over behaviorism. what about jeffrey dahmer?

Jane-

     Hmmm. That's a good question. I admit, I am not well-versed in the ideologies of behaviorism. From what I understand, it states behavior "can be described and explained without making reference to mental events or to internal psychological processes." (I am using this as my source and for my own education!) Being a neuroscientist, and thus brain-centric, I am predisposed to think that ignoring mental state isn't the best way to understand behavior. So I'll explain the little bit I know about the relation of behavior to brain biology, and then try to relate it to genetics.

     As you probably know, behavior is a complex, often puzzling facet of animal behavior. One must account for many mental states when trying to understand a given behavior, particularly in response to a given stimuli. Things one might consider are the animal's (or person's) mood, attentional state, emotional history, etc.
     The last century of neuroscience has elucidated the fact that these processes are controlled by and integrated in the brain. We know that certain brain structures are associated with various 'states of personality' (for lack of a better term). We know that serotonin is involved in depression (Prozac and other anti-depressants are thought to work by increasing levels of serotonin in the brain). We know dopamine is involved in reward paradigms - usually, increased dopamine release is correlated with 'feeling good.' We know that the amygdala, located in the anterior tip of the brain's temporal lobe is associated with feeling fear. We also know pre/frontal cortex is involved with understanding consequences and socially acceptable behavior. (the story of Phineas Gage is compelling example of this observation.)

     We don't necessarily know how all these fit together. But we can see that the brain is parceled into subdivisions which account for elements of our personal experience; and in particular, we see the elements which are likely to affect our behavioral response to various stimuli.

     Thus we know that brain biology is somehow involved in controlling behavior. So when things 'go wrong,' we can try to analyze the brains of those who are dysfunctional. I'll present a few examples of things that could be wrong with psychopaths - hopefully, that will help point you in the right direction.
     One thing that has been associated with psychopaths, and with aggression in general, is the levels of serotonin and dopamine in the brain. In brief, people have found that people who commit criminal behavior tend to have lower levels of serotonin in their brain than the normal population.

Some links to this point:
http://web.sfn.org/content/Publications/BrainBriefings/seroton in.html
http://hubel.sfasu.edu/courseinfo/articles/physio_psychopatho logy.ht ml
http://21 6.117.159.91/crimetimes/97d/w97dp4.htm

     One of those articles also suggests that the psychopaths have abnormal levels of activity in their amygdalas, as well as their prefrontal cortices. Perhaps this abnormal activity makes them unable to feel fear or worry about jail and death. Probing the literature for these topics should provide you a bounty of info concerning their relation to and importance in 'socially acceptable' behavior.

     The question then is: how do these findings relate to genetics per se? When people refer to something as being genetic, they often mean 'hereditary,' as in a trait which is passed down from one's parents and are thus not due to the organism's experience. But we know that the brain is very malleable, and exposure to trauma (both physical and psychological) can lead to profound changes in the brain structure, biochemistry, and function. Therefore, when we consider the findings that serotonin levels are lower in criminals and psychopaths, we can't immediately conclude that they were born with low levels of serotonin, or that their amygdalas developed improperly because of a genetic abnormality. Much more research is needed to ask those questions properly.
     All we can say is that expression of certain genes may be abnormal in a psychopath, but we don't know if they were born that way or if their brain responds that way because of developmental circumstances. In Dahmer's case, some think that the illness his mother bore in pregnancy is responsible. This would suggest a developmental, though not necessarily hereditary, disturbance leading to his behavior.

     I hope this gets the ball rolling for your research. There must be several textbooks of biological psychology which cover these topics in more depth - they'll give good overviews and help direct you to some relevant literature.

-Alex G
cgoddard@fas.harvard.edu