As individual people, embedded in our daily lives, of course we're interested in what makes one person different from another. We've got to hire one person and not another, marry one person and not another.

Today we take it for granted that war happens in smaller, poorer and more backward countries.

I like ice hockey. No one is ever going to ask me to write about that as a metaphor for life.

In fact, without a specification of a creature's goals, the very idea of intelligence is meaningless. A toadstool could be given a genius award for accomplishing with pinpoint precision and unerring reliability, the feat of sitting exactly where it is sitting. Nothing would prevent us from agreeing with the cognitive scientist Zenon Pylyshyn that rocks are smarter than cats because rocks have the sense to go away when you kick them.

The European wars of religion were more deadly than the First World War, proportionally speaking, and in the range of the Second World War in Europe. The Inquisition, the persecution of heretics and infidels and witches, they racked up pretty high death tolls.

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.

Without goals the very concept of intelligence is meaningless