“Butterworth is slightly impatient with this chicken and egg question - which comes first, zeal or hard work? He says that “if, for whatever reason, you start working hard at mathematics when all your classmates don’t, then the teacher is going to favour you, so you’re going to get external rewards, and you’re going to get the internal rewards of being able to do something rather well that your mates aren’t so good at, and so you’ll start off a virtuous circle of external rewards, internal rewards, you work a bit harder, you get even farther ahead of your classmates, who aren’t actually putting in the time. So it wouldn’t be surprising that if random people who for some reason select to pursue maths on the whole get rewarded because they are going to be better than their peers.”