Defending the Self: The Role of Oxytocin in Responses to Psychological Threat.

Oxytocin (OT) is widely characterized as a prosocial neuropeptide, yet its effects are context-dependent and extend beyond affiliation. Drawing on recent evolutionary perspectives, we advance a framework in which OT supports the defense and enhancement of positively biased self-views. This function is distinctly human because it relies on self-reflection and symbolic self-representation. To assess this account, we synthesize evidence across intrapersonal, social comparison, and social evaluation contexts. Converging findings indicate that OT modulates affective, cognitive, and behavioral processes relevant to self-protection. In particular, OT impacts both proactive (e.g., information selection, non-cooperation) and reactive (e.g., aggression, cognitive distortion) strategies that serve to protect desirable self-views. This self-protection account offers a unifying explanation for heterogeneous and sometimes paradoxical OT effects by reframing them as context-sensitive expressions of self-defense. Common and distinct mechanisms through which OT and the structurally homologous neuropeptide vasopressin contribute to self‑protection are delineated. We conclude by situating the account relative to prevailing theoretical models, delineating priorities for future research, and outlining clinical implications for conditions characterized by self‑protection deficits.