Brains distinguish between an Us and a Them in a fraction of a second. Subliminal processing of a Them activates the amygdala and insular cortex, brain regions that are all about fear, anxiety, aggression, and disgust.

The most important point of [Susan] Fiske's work is that it provides a taxonomy for our differing feelings about different Thems - sometimes fear, sometimes ridicule, sometimes contemptuous pity, sometimes savagery.

The frontal cortex doesn't even fully develop until age 25, which is wild!

Most people who do a lot of exercise, particularly in the form of competitive athletics, have unneurotic, extraverted, optimistic personalities to begin with. (Marathon runners are exceptions to this.)

Digestion is quickly shut down during stress…The parasympathetic nervous system, perfect for all that calm, vegetative physiology, normally mediates the actions of digestion. Along comes stress: turn off parasympathetic, turn on the sympathetic, and forget about digestion.

Individual differences in testosterone level predict very little about differences in aggression.

Only humans invent moralizing gods who monitor our behavior.