I have a confused array of feelings and thoughts about violence, aggression, and competition. Just like most humans. (Location 116)

we don’t hate violence. We hate and fear the wrong kind of violence, violence in the wrong context. (Location 126)

Because violence in the right context is different. We pay good money to watch it in a stadium, we teach our kids to fight back, we feel proud when, in creaky middle age, we manage a dirty hip-check in a weekend basketball game. Our conversations are filled with military metaphors—we rally the troops after our ideas get shot down. Our sports teams’ names celebrate violence—Warriors, Vikings, Lions, Tigers, and Bears. We even think this way about something as cerebral as chess—“Kasparov kept pressing for a murderous attack. Toward the end, Kasparov had to oppose threats of violence with more of the same.”1 We build theologies around violence, elect leaders who excel at it, and in the case of so many women, preferentially mate with champions of human combat. When it’s the “right” type of aggression, we love it. It is the ambiguity of violence, that we can pull a trigger as an act of hideous aggression or of self-sacrificing love, that is so challenging. (Location 127)

Putting facts into nice cleanly demarcated buckets of explanation has its advantages—for example, it can help you remember facts better. But it can wreak havoc on your ability to think about those facts. This is because the boundaries between different categories are often arbitrary, but once some arbitrary boundary exists, we forget that it is arbitrary and get way too impressed with its importance. (Location 175)

In other words, when you think categorically, you have trouble seeing how similar or different two things are. (Location 182)

If you pay lots of attention to where boundaries are, you pay less attention to complete pictures. (Location 183)

Thus, it is impossible to conclude that a behavior is caused by a gene, a hormone, a childhood trauma, because the second you invoke one type of explanation, you are de facto invoking them all. (Location 208)

A “neurobiological” or “genetic” or “developmental” explanation for a behavior is just shorthand, an expository convenience for temporarily approaching the whole multifactorial arc from a particular perspective. (Location 210)

Maybe I’m just pretentiously saying, “You have to think complexly about complex things.” Wow, what a revelation. (Location 212)

It can be far more than a mere academic matter when a scientist thinks that human behavior can be entirely explained from only one perspective. (Location 251)

While a few other species have regular nonreproductive sex, we’re the only ones to talk afterward about how it was. (Location 268)

What occurred in the prior second that triggered the behavior? This is the province of the nervous system. What occurred in the prior seconds to minutes that triggered the nervous system to produce that behavior? This is the world of sensory stimuli, much of it sensed unconsciously. What occurred in the prior hours to days to change the sensitivity of the nervous system to such stimuli? Acute actions of hormones. And so on, all the way back to the evolutionary pressures played out over the prior millions of years that started the ball rolling. So we’re set. (Location 303)

Here’s an example, namely the ways I think about the word “competition”: (a) “competition”—your lab team races the Cambridge group to a discovery (exhilarating but embarrassing to admit to); (b) “competition”—playing pickup soccer (fine, as long as the best player shifts sides if the score becomes lopsided); (c) “competition”—your child’s teacher announces a prize for the best outlining-your-fingers Thanksgiving turkey drawing (silly and perhaps a red flag—if it keeps happening, maybe complain to the principal); (d) “competition”—whose deity is more worth killing for? (try to avoid). (Location 314)