Part of the success of the gay marriage initiatives had to do with the acknowledgement that being gay was less a choice but more a matter of biology. Science found some of the genetic and endocrinological underpinnings that made being gay genetically influenced (but not determined, there's a difference). In the legal arena, it has long been accepted that certain conditions, such as schizophrenia, can be a mitigating factor in determining guilt, and that acceptance has had to do with, again, a determination that such conditions are less a matter of choice and more of biology. The Not Guilty By Reason of Insanity verdict, although rather rare, has been around for many decades even though the actual biological evidence from more modern brain studies such as CAT and PET and SPECT and MRI and fMRI are relatively recent. With these advances in neuroscience, more and more conditions previously thought mainly psychological in origin are having their biological causes discovered. The two most interesting to me, and I guess to the legal system, are drug/alcohol addiction and sociopathy/psychopathy. With the addictions, there seems to be a degree of choice: one must actively imbibe a substance for it to be a factor in criminality. However, with sociopathy/psychopathy, there seems to be less choice involved. If we look at this latter condition ( I find little to distinguish them from one another: psychopathy seems to be just a more evil form of sociopathy) there has been evidence from the abovementioned brain studies that the sociopath/psychopath has measurable differences in certain brain areas not seen in more moral human beings. If it has not already been used by some hotshot defense attorney, I can expect this evidence to be brought to bear as a way for some criminals to escape their punishment. Once again, technology will force a major rethinking of law and governance, as it should with regard to gun control and privacy, but I do not await the day when your basic criminal psychopath walks free because of how his brain was constructed.