It's probably even the case that if you stoked up some Buddhist monks with tons of testosterone, they'd become wildly competitive as to who can do the most acts of random kindness.

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

But if you get chronically, psychosocially stressed, you're going to compromise your health. So, essentially, we've evolved to be smart enough to make ourselves sick.

The regulation of genes is often more interesting than the genes themselves, and it's the environment that regulates genes.

Pulling a gun's trigger can be an appalling act. But if it is suicidal drawing fire to save someone, it has an utterly different meaning. Placing your hand on someone's arm can be an act of deep compassion or the first step of betrayal. The punch line? It's all about context, and the biology of context is vastly more complicated than the biology of the behavior itself.

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.

Essentially, we humans live well enough and long enough, and are smart enough, to generate all sorts of stressful events purely in our heads.