The study looked at whether giving oxytocin changes how much people (or rats) trust information from others. Across several experiments, oxytocin didn’t consistently boost this kind of trust, and results varied a lot depending on who was involved and the situation.

Oxytocin (OT) is a hypothalamic neurohormone extensively studied for its role in affiliative behavior, yet its influence on epistemic trust, or trust in communicated knowledge, has received less attention. We synthesized evidence from human experiments on epistemic trust and rodent experiments using the social transmission of food preference (STFP) paradigm. During STFP, rodents learn about food safety through interaction with a conspecific, a learning process that may engage cognitive processes functionally parallel to elements of human epistemic trust. We combined effect sizes from five human studies (N = 414) and three rodent studies (N = 330), revealing no significant overall effect of OT administration on epistemic trust in humans (g = 0.25, 95 % CI: -0.25 to 0.75, p = .23) or STFP acquisition in rodents (g = -0.02, 95 % CI: -0.60 to 0.56, p = .84), with substantial heterogeneity across samples. Narrative syntheses suggest that OT may dynamically modulate epistemic trust and STFP acquisition based on informant and recipient characteristics, as well as contextual factors. By integrating these complementary lines of evidence, the current study advances a translational framework to test the allostatic model of OT and probe underlying neural mechanisms. Our findings may therefore guide future research, addressing more precise questions regarding OT effects, and ultimately improve clinical outcomes.