HealthDay News (via Forbes.com) reports on a new study showing that a lack of oxytocin in male mice made them more aggressive.
The male mice were highly aggressive, quicker to attack intruders and more likely to fight them for a longer period. It wasn't clear, however, if the missing hormone might lower some other types of aggression.
The male mice were also more likely to forget the identity of females they had met.
As for the female mice, they sometimes forgot to retrieve their babies when they wandered off.