ABSTRACT
Pulp-fiction thrillers regularly exploit the idea that old people need little sleep and that any sleep that they get is shallow. A light-sleeping elderly victim is the first to sense a creeping perpetrator. Psychologists have always had to accept the thankless task of testing folklore. Research on the effects of loss of sleep and drowsiness on mental competence has been driven by interest in the effects of irregular sleep patterns on relatively young people, military personnel and young workers on rotating shifts. Surveys find that shift workers in their fifties and sixties, who are much younger and fitter than people of my old or old generation, are more debilitated by night work and adapt less completely to difficult shift rotations than their colleagues in their thirties and early forties. Even conspicuously brisk and energetic young adults experience regular fluctuations in physiology and so in mental competence during the 24-hour day and night cycle.
