Mapping the Structural Brain Network of Psychopathy: Convergent Evidence from Humans and Chimpanzees.

Psychopathy, a condition marked by profound emotional and interpersonal deficits, has long been hypothesized to arise, in part, from structural abnormalities in the brain. Yet neuroimaging studies have reported widely disparate findings, yielding inconsistent conclusions. Here, we sought to resolve these discrepancies using a novel network-based framework. We conducted a systematic literature search of PubMed, Web of Science, EMBASE, and SCOPUS, identifying 18 studies (20 independent samples) examining whole-brain grey matter volume in psychopathy. Using morphometric data from 1,000 healthy participants, we identified the principal covariation pattern across studies, revealing a consistent network architecture primarily encompassing paralimbic regions and insular cortices. We next examined whether psychopathic and personality traits predicted inter-individual structural variation within this network in humans (n = 107) and chimpanzees (n = 148). Significant effects were observed in both species, explaining 15-16% and 42-48% of the variance, respectively. These findings indicate that psychopathy is best characterized by deficits in a distributed neural system rather than isolated regions, providing a unifying account of decades of inconsistent findings and advancing our understanding of its clinical, biological, and evolutionary bases.