A study from the Univ. of Calif. proposes a link between female friendship & physical health. The study suggests women respond to stress with a cascade of brain chemicals that drive them to bond with other women they can identify with. That bonding behaviour, in turn, leads to a surge of the hormone oxytocin in the brain, which further counters stress & calms your mood. According to Lhotsky, this new theory may help explain why women live longer than men.