Psychopathy has often been characterized as a form of mental illness or disorder, the psychopath being deeply disturbed, often violent, and always unscrupulous, completely lacking in empathy for others, or possibly not even having the ability to understand what empathy is. Another characterization of psychopathy is that it is adaptive, a strategy that increases one’s fitness. In this light, psychopathy is a cheating strategy, one which makes use of others’ general trust for the psychopath’s own ends. Which hypothesis is the better fit?
Some ingenious researchers found a way to test these hypotheses. Do psychopaths harm relatives? Nepotistic patterns of violent psychopathy: evidence for adaptation?.
Contrary to the mental disorder hypothesis, we show here in a sample of 289 violent offenders that variation in psychopathy predicts a decrease in the genetic relatedness of victims to offenders; that is, psychopathy predicts an increased likelihood of harming non-relatives. … Although psychopathy was negatively associated with coresidence with kin and positively associated with the commission of sexual assault, it remained negatively associated with the genetic relatedness of victims to offenders after removing cases of offenders who had coresided with kin and cases of sexual assault from the analyses. These results stand in contrast to models positing psychopathy as a pathology, and provide support for the hypothesis that psychopathy reflects an evolutionary strategy largely favoring the exploitation of non-relatives.
Psychopathy as a cheating strategy is dependent on the trust of others. What will happen as social trust declines, as is happening now? Psychopaths ought to be less successful, as people will be more wary of potential cheaters and more distrustful overall.
Maybe psychopathy could be viewed as an extreme form of r-selection. They put great effort into achieving a robust sex life, have little thought for the morrow, put little effort into parental investment, and are completely selfish.
Also, given the recent events in Rotherham and other English cities, it occurs that the Pakistani groomers acted like psychopaths toward their victims: smooth and calm and giving when it suited their ends, violent at other times, ruthless, focused on sex. Yet one wonders how they behaved toward their own kin: nothing like that, one imagines.
For psychopaths, everyone else except blood relatives are an out-group.