What does the frontal cortex do? Gratification postponement, executive function, long-term planning, and impulse control. Basically, it makes you do the harder thing.

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

Naturally, things are more complicated - those groovy, pro-social effects of oxytocin apply to how we interact with in-group members.

Oxytocin is a Teflon hormone - bad news rolls off it.

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.

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

Finish this lecture, go outside, and unexpectedly get gored by an elephant, and you are going to secrete glucocorticoids. There's no way out of it. You cannot psychologically reframe your experience and decide you did not like the shirt, here's an excuse to throw it out - that sort of thing.