Oxytocin boosts trust in low-trust men

A new study published in PNAS on August 11, 2026, provides robust evidence that intranasal oxytocin selectively increases trusting behavior in men with a low disposition to trust. The international research team, led by Ernst Fehr of the University of Zurich and including Bodo Vogt, Paul Bengart (Otto von Guericke University Magdeburg), and Carolyn Declerck (University of Antwerp), recruited 359 men with low dispositional trust. Participants randomly received oxytocin or placebo and then played an anonymous trust game. Those receiving oxytocin entrusted about 15% more money than the placebo group. A pooled analysis of 578 men showed a nearly 17% increase in trusting behavior. The effect was selective, not general, and the biological mechanisms remain unexplained. The study confirms earlier findings from 2005 with a larger sample and predefined hypothesis.