Pain, Bonding and the Kindness of Strangers

In a long post, Mothersvox ponders the biochemistry of surrender. After she was flattened by a bike messenger, she felt waves of joy as she lay there.

Each person who came by to help suddenly looked lovelier than the last, and the blue of the winter sky was so exquisite that it nearly brought tears to my eyes. How was it that everything and everyone had suddenly become of so unaccountably lovely?
...
What, I wondered, happens when we're suddenly injured? What happens that inures us to the pain of our injuries and renders our impression of others beneficent?

My thought was oxytocin.

I've never seen anything written about this, but it absolutely makes sense to me.

Oxytocin is part of the parasympathetic nervous system that moderates fight-or-flight impulses. It also reduces pain and makes us feel bonded to others. If there is a "surrender response," it may be greater in females; what UCLA psychologist Shelley Taylor calls "tend and befriend" behavior.

In her book, "The Tending Instinct," Taylor explains that in stressful or dangerous situations, women are more likely to close ranks, gathering with other women and children to support each other, while men are more likely to jump up and fight to protect the family, clan or whatever. This is (simplistically) because men have higher levels of vasopressin -- the jump up and protect hormone -- and more testosterone, which mutes oxytocin. Women's higher levels of estrogen increase the calming, bonding effects of oxytocin.

Throughout evolution, women -- smaller, weaker and encumbered with children -- would have a better chance of surviving or enabling children to escape by giving up when attacked.