In humans several experimental pharmacological studies have found positive effects of intra-nasally administered OT on a wide spectrum of social behaviors, including trust (17), generosity (18), judgments of facial trustworthiness and attractiveness (19), face recognition (20), parochial altruism (21), emotion perception (22), social behaviors in autism spectrum disorder (23, 24) and more pair-bonding related phenotypes such as communication and behavior in a conflict discussion between couples (25). Studies have also shown associations between plasma levels of OT and romantic bonding related outcomes (26). Moreover, there is also evidence from neuroimaging studies suggesting effects of OT treatment on amygdala activity (27–29), a brain region known to be of importance for regulation of social behaviors. Further, genetic studies have shown that variation in OXTR is associated with social behaviors in humans such as empathy (30) attachment style in patients with depression (31), social cognition in ADHD (32), emotional support seeking (33), prosocial temperament (34), maternal sensitivity (35), prosocial decision making (36) and autism (37–46). Finally, variation in OXTR has been associated with the functioning (34) as well as the size of the
