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An evil disposition

Gene ExpressionBy Razib KhanSeptember 12, 2012 11:14 AM


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The thread below on the possibility of pedophilia being a biologically mediated tendency rapidly degenerated, to no one's surprise. As I didn't have the time to engage in strict moderation I had to close it. And I don't want to reopen that particular topic. Rather, I want to focus on the issue of psychopathy exhibiting some genetic disposition. I want to assert immediately that I'm not positing that you're born a psychopath like you're born with red hair. Rather, psychopathy is a set of traits whose upstream causes can be both genetic and non-genetic. In fact some cases of psychopathic behavior seems to be rooted in extreme social and psychological deprivation (e.g., orphanages in underdeveloped countries). Interestingly, this may be a case where the environmental input reshapes the developing brain, so that even though the individual may lack a genetic predisposition toward a particular psychology, they may now be biological oriented toward all the traits associated with psychopathy because of the nature of their neurological development. Going to the model where some people exhibit a genetic disposition toward psychopathy, there are two dichotomous models I'd like to outline. First, there is a model where psychopathy is a deviation from the "wild type." Basically, a genetic "mistake." This is my own suspicion. Psychopaths may have a higher mutational load, for example. If the tendency runs through families it may simply be that the family has more mutations than in the norm in the human population. This model has some analogy to the case of environmental perturbations. Psychopathy might be a "born that way" trait, but it is a deviation from the ideal state for an individual as any disease might be. But there's another model. Here's the Wikipedia definition of psychopathy:

...a personality disorder that has been variously described as characterized by shallow emotions (in particular reduced fear), stress tolerance, lacking empathy, coldheartedness, lacking guilt, egocentricity, superficial charm, manipulativeness, irresponsibility, nonplanfulness, impulsivity, and antisocial behaviors such as parasitic lifestyle and criminality. There is no consensus about the symptom criteria and there are ongoing debates regarding issues such as essential features, causes, and the possibility of treatment.

What if psychopathy is not a "mistake" or deviation, but simply another morph or behavioral strategy within the human population? At low frequencies psychopaths may have relatively high fitness, because they can easily deceive and manipulate normal humans. As they increase in frequency the general population will begin to exhibit suspicion of others, and the psychopathic advantages will rapidly diminish. A population with too many psychopaths would probably not function, as everyone tries to screw everyone else over. The point here is that in this second model psychopathy is not really a mental disease...but another way to be human. Part of human "neurodiversity," so to speak. Psychopaths basically are our "evil twins". Their moral universe is radically different, and that's a feature for them, not a bug. Does any of this matter in terms of how we relate to or treat psychopaths? Personally, I don't think so. But all this should make us reflect on the power, or lack thereof, of the "born that way" rationale. Whether psychopathy is purely environmental, or genetic, or developmental stochasticity, it is not good. Of course in the last sentence I speak as a normal human.

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