Researchers studied how a hormone called vasopressin affects the brain and emotions during social situations. They gave 48 healthy male volunteers either a vasopressin nasal spray or a placebo spray. Then, while inside an MRI scanner, the men performed tasks that involved comparing themselves to a friend and a stranger.
The study found that the vasopressin spray changed how the men felt and how their brains worked. Men who received vasopressin reported stronger competitive feelings when thinking about a stranger's social status. Their brain scans also showed less distinction in a key social brain region when thinking about a stranger versus themselves or a friend.
No safety issues were reported in this short study, but it was not designed to look for side effects over time. The main reason to be careful is that this was a single, small study only in healthy young men. The results show how a hormone can influence brain circuits related to social comparison, but this does not mean the spray is a treatment. The findings offer a clue for future research into conditions where social perception is difficult, but much more work is needed.