Biologists at Princeton University looked closely at relationships in baboon packs, which, like wolves, have an "alpha male" at the top.
The report in the journal Science finds these males have very high stress hormone levels.
The reason? Fighting off challengers for choice females and defending rank seem to be tough on the "prime" primates.
So what does this mean for humans?
Researchers say it could lead to a better understanding on the impact of stress hormones on our health and how our social rankings contribute to stress.