At the beginning of Chapter 2, Pinker takes us through a thought exercise: If we met an alien, “what would it have to do to make us think it was intelligent?” (61). Pinker summarizes the criteria for intelligence as acting using rules based on some relation to reality or logical inference, pursuing a goal or desire, and using the rational rules to pursue the goal in different ways depending on the obstacles in place. Not meeting these rules indicates that the being is not intelligent. Magnets, for example, are obeying physical laws in moving toward one another, but they can’t be said to “want” to be touching, and they can only move in a direct line. If an obstacle appears, they remain on either side of the obstacle, as close as they can physically get; They do not attempt other means to get closer to each other.

These rules bring up the question of why people choose the goals they choose. Pinker points out that we still use common sense and intuitive psychology, our internal sense of how our mind and other people’s minds work, to understand why people behave the way they do. We do not look to models or algorithms.