Krupp Daniel Brian, Sewall Lindsay A, Lalumière Martin L, Sheriff Craig, Harris Grant T
Department of Mathematics and Statistics, Queen's University Kingston, ON, Canada.
Front Psychol. 2012 Aug 28;3:305. doi: 10.3389/fpsyg.2012.00305. eCollection 2012.
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.
精神病态者经常通过自私、反社会且往往具有暴力性的行为来无视社会规范。通常被认为患有精神障碍，然而最近的证据表明，精神病态者正在实施一种运作良好的策略，即便这种策略不择手段，且在历史上是以牺牲他人为代价来提高生殖成功率。自然选择本应青睐那些使近亲免受伤害的策略，因为影响基因亲属健康状况的行为有助于个体的广义适合度。相反，有证据表明精神障碍会扰乱旨在保护亲属的心理机制。因此，关于精神病态的精神障碍和适应性解释产生了相反的假设：在前一种解释中，精神病态应与亲属受害率的增加相关，而在后一种解释中则不然。与精神障碍假设相反，我们在289名暴力罪犯的样本中发现，精神病态的差异预示着受害者与罪犯的基因关联性降低；也就是说，精神病态预示着伤害非亲属的可能性增加。由于暴力行为中的亲缘抑制可能是由分散居住或亲属识别导致的，我们研究了精神病态对（1）罪犯及其亲属的分散居住情况以及（2）性侵犯频率（作为亲属识别的一个窗口）的影响。尽管精神病态与与亲属共同居住呈负相关，与性侵犯的实施呈正相关，但在从分析中剔除与亲属共同居住的罪犯案例和性侵犯案例后，它与受害者与罪犯的基因关联性仍呈负相关。这些结果与将精神病态视为一种病理状态的模型形成对比，并为精神病态反映一种主要有利于剥削非亲属的进化策略这一假设提供了支持。
