As long as experiencing your optimal level of good stress doesn't damage others, it's hard to objectively define where normal enjoyment of stimulation becomes adrenaline junkiehood.
Robert M. SapolskyIt's probably even the case that if you stoked up some Buddhist monks with tons of testosterone, they'd become wildly competitive as to who can do the most acts of random kindness.
Robert M. SapolskyGive lab rats oxytocin and, according to that meme, they get better at talking about their feelings and sing like Joan Baez.
Robert M. Sapolsky