It is almost on a daily basis that we use talk about character traits to explain and predict behaviour. 'John is a reliable guy, I'm sure he will help us move on the weekend, ' or 'Anna is shy, I doubt she will come out for karaoke'. We say that the reason Gary insulted my daring haircut is that he is rude. We choose a brave man to go on the dangerous mission. We need a friendly person to work at our new shop. And when gentle Sarah suddenly snaps...