Psychopathy, in many ways – though not completely, runs counter to evolutionary psychology.  Evolutionary psychologists believe that many human behaviors have been hardwired over time due to the evolutionary desire to procreate and otherwise propagate the species into future generations.  This is not a stretch by any means; we see this with dogs that have been selectively bred over time.  German Shepherds, for instance, were bred in part for their protective personalities.  Poodles, not so much.

I was listening to a psychology professor lecture on evolutionary psychology recently.  She was discussing how evolution has incorporated behaviors into the human psyche.  Even homosexual couples that will never reproduce are subject to this evolutionary drive:

Even if you will never have children, you still are subject to these evolutionary pressures to ensure the survival of your genes.  Unless you are pathological, a psychopath, you have a drive to protect your siblings and their children and a desire to see the species live into the next generation.

The anecdote, while brief, sums up an important point regarding the psychopath.  We tend to not care about anyone’s survival except occasionally our own.

Now, the obvious counter-example would be with regards to the psychopath’s sexually promiscuous behavior.  For the male especially, this can be seen as a frenzied attempt to propagate his genes by any means necessary.  In general, however, the psychopath is unconcerned about the survival of the species via the preservation of others.  Other individuals are tools to be used and targets to pillage.

So then, what is the evolutionary purpose of the psychopath?  Does there have to be a purpose?  A good friend of mine remarked that psychopaths may be needed in order to do the “dirty” deeds of society: taxidermists, surgeons, butchers, morticians, etc.  Clearly these jobs are not required by everyone, so our relatively small numbers could be sufficient.  If anyone knows of an academic article that sheds light on this question, let me know.  It is an interesting question to ponder.

On the other hand, an interesting non-evolutionary model to consider is a predator-prey model, such as the Lotka-Volterra model.  Those familiar with multivariate calculus know that the relationship of prey to predators is stable only so long as neither the number of prey nor predators reach highly saturated or desolate levels.  A land full of prey, due to a lack of predation, dies out as the prey far exceed the resources that can sustain them.  Likewise, if the number of  predators are too high, the prey go extinct, shortly followed by the predators as their food source was completely consumed.

Extending this model to psychopaths and neurotypicals, combined with the thoughts regarding “dirty” jobs that NTs may shy away from, is an interesting thought experiment.  If there were none who lacked empathy, could the neurotypical remainder survive in doing the dirty but necessary jobs left in their absence?  If the number of psychopaths were too large, would they survive the constant backstabbing within the in-group?

I would love to see an evolutionary psychology article explaining the existence of the psychopath.  In the meantime, these are interesting questions to explore on one’s own.