Currently, Western people live relatively healthy lives until their 60s, when morbidity starts to accumulate until death. A concern for population health is that death will be postponed to older and older ages, but morbidity will not. An important goal, therefore, is not only to increase life expectancy but to ensure that added years at the end of life are healthy years of living and to improve the quality of longer lives. To achieve this goal, aging research must enable still-healthy young people to age more slowly and stay young longer. With this goal in mind, our work is focused on two areas. First, we have sought to advance and test methods to quantify differences among healthy individuals in their pace of aging. Our hope is that these methods will be incorporated into research about the causes of accelerated aging and into intervention studies that seek to slow aging in adults before the onset of age-related diseases. Second, we are focusing on identifying the personal history characteristics that are implicated in accelerated aging.