Genes are important for understanding our behavior. Incredibly important - after all, they code for every protein pertinent to brain function, endocrinology, etc.

To out-group-members, oxytocin makes you crappier - less cooperative and more preemptively aggressive. It's not the luv hormone. It's the in-group parochialism/xenophobia hormone.

It's great to have a buff frontal cortex to do that harder thing - for example, help a person in need rather buy some useless, shiny gee-gaw.

Stress is not a state of mind... it's measurable and dangerous, and humans can't seem to find their off-switch.

We live well enough to have the luxury to get ourselves sick with purely social, psychological stress.

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

How much you groom somebody else is more important than who grooms you.