The Better Angels of Our Nature: Why Violence Has Declined

by Steven Pinker

Behavioral genetics confirms that aggressive tendencies can be inherited, and that gives natural selection material to work with in shifting the average violent tendencies of a population.

allowing wives to bet that their husbands would die, both of which are technically accurate descriptions of what life insurance does.

For all their foolishness, modern societies have been getting smarter, and all things being equal, a smarter world is a less violent world.