Please check only one option: __ Brains __ Balls
January 25, 2006 9:35 AM Subscribe
Monogamists have bigger brains.
More precisely, female monogamy in bats makes their male partner's brains bigger and their balls smaller, while female promiscuity in another bat species caused males to have huge balls and teeny brains. Can trusting your partner not to cheat lead to greater intellectual greatness? Via.