Psychopaths routinely disregard social norms by engaging in selfish, antisocial, often violent behavior. Commonly characterized as mentally disordered, recent evidence suggests that psychopaths are executing a well-functioning, if unscrupulous strategy that historically increased reproductive success at the expense of others. Natural selection ought to have favored strategies that spared close kin from harm, however, because actions affecting the fitness of genetic relatives contribute to an individual’s inclusive fitness. Conversely, there is evidence that mental disorders can disrupt psychological mechanisms designed to (...) protect relatives. Thus, mental disorder and adaptation accounts of psychopathy generate opposing hypotheses: psychopathy should be associated with an increase in the victimization of kin in the former account but not in the latter. 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. Because nepotistic inhibition in violence may be caused by dispersal or kin discrimination, we examined the effects of psychopathy on (1) the dispersal of offenders and their kin and (2) sexual assault frequency (as a window on kin discrimination). 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. (shrink)

"Sheriff’s text moves the "guess" to a new level of understanding, while integrating much of Peirce’s philosophy, and provokes many questions." —Society for the Advancement of American Philosophy Newletter "The purpose of Sheriff’s work is to expound Peirce’s unified theory of the universe—from cosmology to semiotic—and to discuss its ramifications for how we should live. He concludes that Peirce has given us a theory we can live with. The book makes an important contribution to philosophy of life and to the (...) humanities in general."—Nathan Houser "In clear and concise prose, Sheriff describes Peirce’s ‘theory of everything,’ a vision of cosmic and human meaning that offers a positive alternative to popular pessimistic and relativistic approaches to life and meaning." —Peirce Project Newsletter. (shrink)