The new clan of treated phenylketonurics (1) cannot be assumed to be a happy one, or one with a high proportion of well adjusted individuals. Conceding for the moment that the Phenylketonuric, if he sticks to his diet, will retain much of his intelligence, it is safe to predict that he will be miserable. One of his life's basic processes for satisfaction, his food, has been seriously tampered with, and replaced by a conflict. Eggs, milk, cheese, meat, fish, poultry, most fruit, even ordinary bread, are taboo for his table. He will consume a diet which will be cunningly prepared and flavoured, but he can hardly say that he “eats food”. His fate is that the satisfaction—and the surcease—of incorporating various articles of food does not exist for him, or only in an attenuated form.