I am still not very far into Nicholas Wade’s Troubled Inheritance, but I found out something I did not know but which fits well with my world view. It turns out that oxytocin is not some generic “trust hormone” that makes one feel at ease with all sorts of strangers. Instead, describing the implications of recent research by Carsten de Dreu, Wade writes,

Oxytocin engenders trust toward members of the in-group, together with feelings of defensiveness toward outsiders.