Study reveals psychopaths have significant differences in brain structure -- grey matter.

[ljm2002]

9. I wouldn't jump to conclusions...

...as to cause and effect here. While it is possible that psychopaths occur because of differences in brain structure, it is also possible that the psychopaths' brain structures are different because of their behavior over the years -- i.e., they didn't use those parts of the brain so they atrophied somewhat or at any rate, stopped developing.

I'm not saying it's one or the other; however, it seems to me that these things are often presented as obvious cause-and-effect relationships when the truth may be more complex.