Many high-functioning older adults are satisfied with their sleep, even though it is of objectively poorer quality than that of younger adults. When the various factors that can disrupt sleep are screened out, aging adults can expect to undergo little change in their sleep relative to those in the early to middle adult life span. Nevertheless, even successfully aging older adults can expect on average to be earlier to bed and to rise, and to be less tolerant of circadian phase shifts, such as those induced by jet lag, than younger similarly health adults.