Decreased prosocial behaviour and altered self and other reward processing are key features of psychopathic traits36,37. Psychopathic traits are characterised by dysfunctional affective-interpersonal features38,39 and also include an antisocial behavioural dimension40. Levels of these traits range from clinically defined psychopathy, a severe personality condition linked to poor life outcomes, violence and criminality41,42,43, to lower subclinical levels of psychopathic traits in the general population. This conceptualisation of psychopathy as dimensional, rather than categorical, reflects the Research Domains of Criteria (RDoC) approach to psychiatry44. Evidence of similar behavioural and neural profiles between community samples with high levels of psychopathic traits and those with clinical diagnoses of psychopathy45 is consistent with this RDoC approach. Self-report measures of psychopathic traits mirror the latent structure of clinical psychopathy measures as comprising socio-emotional and behavioural dimensions but are distinct from a clinical diagnosis of psychopathy. These subclinical self-report measures, such as the Self-Report Psychopathy Scale (SRP)40 used here, can be administered in behavioural studies to index the range of scores found in the general population. The SRP captures psychopathic traits on two dimensions labelled: ‘affective-interpersonal’ (lack of empathy and guilt) and ‘lifestyle-antisocial’ (impulsive and antisocial behaviours)40.
Intriguingly, preliminary evidence suggests that ageing may also be associated with changes in self-reported psychopathic traits46, which could have important implications for our understanding of an ageing population. In community samples, ageing is associated with a decrease in the socio-emotional and behavioural dimensions of the SRP47. These studies highlight the importance of assessing how differences in self-reported psychopathic traits could map on to differences in prosocial behaviours.