Persecutory delusions: reminiscence of ancestral hostile threats?

Recent studies suggest that both the form and the content of persecutory delusional beliefs may reflect pathological exaggerations of evolved psychological mechanisms for dealing with social threat recognition. Here, we tested the hypothesis first put forward by Walston et al. [Evolution and Human Behavior 19 (1998) 257–260] that sex differences in the content of persecutory delusions reflect divergent ancestral hostile social threats, in a prospective study of two samples of German and Russian patients with delusions of persecution. Deluded men and women differed significantly in their attributions of perceived threats. The majority of men felt persecuted by groups of hostile strange males, whereas women projected their paranoid fears onto familiar people of their social environment, largely irrespective of psychiatric diagnosis or cultural background. In contrast to our predictions, however, both men and women with persecutory delusions were most frightened of physical violence. Fear of sexual coercion was only present in a small number of patients. In sum, this study is largely supportive of the hypothesis that the content of persecutory delusions reflects ancestral hostile threats.