Your recollection is almost close :-). He does mention how testosterone even promotes—a few notches up from "regulate"—prosocial behaviour, but only in the right setting:

"In one [study], under circumstances where someone's sense of pride rides on honesty, testosterone decreased men's cheating in a game. [...] Engineer social circumstances right, and boosting testosterone levels during a challenge would make people compete like crazy to do the most acts of random kindness. In our world riddled with male violence, the problem isn't that testosterone can increase levels of aggression. The problem is the frequency with which we reward aggression."

Behave piqued my interest enough to make me pick up a robust neuroscience textbook. (For those curious, I went with the fourth edition of this one, by Bear et al—https://openlibrary.org/books/OL27999902M/Neuroscience. I strongly recommend it; it's written with excellent pedagogic skill.)