A study in 1987-92 assessed the effects of changes in life course on work and careers. Interviews with 150 individuals who remained active or continued to work beyond age 65 showed lifetimes differing greatly from the traditional model. The combination of longer lifetimes and postponement of old age has created a new stage in adult life, a second middle age, and new opportunities. Almost half the group began their period of greatest creativity and productivity at about age 50. Some had three or more career peaks, at about 15-year intervals; others experienced a steady upward progression. None expected such a creative period at this age, but remained active because they enjoyed it. There was no single pattern to finding the most satisfying work; some began early in life and some much later. The study concluded that the urge to develop one's abilities is fundamentally biological, with a number of distinct patterns. This longevity revolution has revealed powerful contradictions in American attitudes about aging. In higher education the impact may be greater faculty persistence, or use of traditional retirement to pursue personal interests. Faculty longevity may come to be regarded as an asset. Continued faculty affiliation with an institution after retirement is recommended. (MSE)