Instinct is the pull inside you that does not come from lessons. A baby holds your finger. A bird builds a nest. You pull your hand off a hot pan before you have a thought. That is instinct: a natural way of acting, or a natural knowing, that nobody taught you. People also use it more loosely: “My instinct says this is a bad idea.” Here they mean a quick inner feeling, not a reason from school. Though actually, scientists keep instinct closer to the animal-and-body kind, and everyday talk lets it sit next to a “gut feeling.” Intuition is the word people often want for a hunch in the mind. You cannot study your way into an instinct, though practice can sit on top of it. The word is ordinary, not fancy.