John Gottmans's been researching relationships, including physiological changes while the partners interact....
It seemed that relationships last to the extent that you select someone whose annoying personality traits don't send you into emotional orbit.
...there's an intimate connection between what's happening to the autonomic nervous system and what happening in the brain, and how well people can take in information — how well they can just process information — for example, just being able to listen to your partner — that is much harder when your heart rate is above the intrinsic rate of the heart, which is around a hundred to a hundred and five beats a minute for most people with a healthy heart.
This backs up an intuition I've had for a very long time--that people can't think when they're angry. A lot of my personal style is based on the desire to have people calm enough that they're capable of thinking.
I've noticed a recent contradiction, though--the above means that I try to be very careful with my own anger. It's as though I'm trying to take complete control of the anger problem, and it's possible that I need a more sophisticated strategy.
Link gotten from dglenn.