So much for right versus left. Mr Brooks also finds that extremists of both sides are happier than moderates. Some 35% of those who call themselves “extremely liberal” say they are very happy, against only 22% of ordinary liberals. For conservatives, the gap is smaller: 48% to 43%. Extremists are happy, Mr Brooks reckons, because they are certain they are right. Alas, this often leads them to conclude that the other side is not merely wrong, but evil. Some two-thirds of America's far left and half of the far right say they dislike not only the other side's ideas, but also the people who hold them.