Behave: The Biology of Humans at Our Best and Worst

by Robert M. Sapolsky

If you pay lots of attention to where boundaries are, you pay less attention to complete pictures.

“The opposite of love is not hate; its opposite is indifference.”

The sympathetic nervous system (SNS) mediates the body’s response to arousing circumstances, for example, producing the famed “fight or flight” stress response.

Crucially, the brain region most involved in feeling afraid and anxious is most involved in generating aggression.

soon we barely notice the fleeting whispers of pleasure caused by leaves in autumn, or by the lingering glance of the right person, or by the promise of reward following a difficult, worthy task.

What was an unexpected pleasure yesterday is what we feel entitled to today, and what won’t be enough tomorrow.

In other words, dopamine is not about the happiness of reward. It’s about the happiness of pursuit of reward that has a decent chance of occurring.

Though the dopamine system is similar across numerous species, humans do something utterly novel: we delay gratification for insanely long times.

We do something even beyond this unprecedented gratification delay: we use the dopaminergic power of the happiness of pursuit to motivate us to work for rewards that come after we are dead

We’re more likely to vote for attractive people or hire them, less likely to convict them of crimes, and, if they are convicted, more likely to dole out shorter sentences.

Post a large picture of a pair of eyes at a bus stop (versus a picture of flowers), and people become more likely to clean up litter.

They proposed that small signs of urban disarray—litter, graffiti, broken windows, public drunkenness—form a slippery slope leading to larger signs of disarray, leading to increased crime.

Testosterone makes us more willing to do what it takes to attain and maintain status. And the key point is what it takes.