The task of evolutionary psychology is not to weigh in on human nature, a task better left to others. It is to add the satisfying kind of insight that only science can provide: to connect what we know about human nature with the rest of our knowledge of how the world works, and to explain the largest number of facts with the smallest number of assumptions.

In many Muslim countries, witchcraft is not only on the books as a crime, but is commonly prosecuted. In 2009, for example, Saudi Arabia convicted a man for carrying a phone booklet with characters in an alphabet from his native Eritrea, which the police interpreted as occult symbols. He was lashed three hundred times and imprisoned for more than three years.

Societies that empower women are less violent in every way.

Just as blueprints don't necessarily specify blue buildings, selfish genes don't necessarily specify selfish organisms. As we shall see, sometimes the most selfish thing a gene can do is build a selfless brain. Genes are a play within a play, not the interior monologue of the players.

If the myth of pure evil is that evil is committed with the intention of causing harm and an absence of moral considerations, then it applies to very few acts of so-called 'pure evil' because most evildoers believe what they are doing is forgivable or justifiable.

Some people think that evolutionary psychology claims to have discovered that human nature is selfish and wicked. But they are flattering the researchers and anyone who would claim to have discovered the opposite. No one needs a scientist to measure whether humans are prone to knavery. The question has been answered in the history books, the newspapers, the ethnographic record, and the letters to Ann Landers. But people treat it like an open question, as if someday science might discover that it's all a bad dream and we will wake up to find that it is human nature to love one another.

The more you think about and interact with other people, the more you realize that it is untenable to privilege your interests over theirs, at least not if you want them to listen to you. You can’t say that my interests are special compared to yours any more than you can say that the particular spot that I am standing on is a unique part of the universe because I happen to be standing on it that very minute.