As you read this chapter, take note of these central ideas:

1. Increased life expectancy and a declining birthrate in the United States and other industrial countries are leading to a trend of “mass longevity” and a large cohort of adults in midlife; very recently, this trend has led to an intense research interest in middle adulthood.
2. Theories about middle adulthood propose that midlife adults are deeply involved in care and concern for the generations to come and that midlife is a time when individuals attempt to find balance in opposing aspects of their lives.
3. Most biological systems reach their peak in the mid-20s, and gradual declines begin after that; by age 50, biological change becomes physically noticeable in most people, particularly changes in physical appearance, mobility, the reproductive system, and in vulnerability to chronic disease.
4. Middle adulthood is the period of peak performance of four mental abilities: inductive reasoning, spatial orientation, vocabulary, and verbal memory. Perceptual speed and numerical ability decline in middle adulthood.
5. There is good evidence of both stability and change in personality in middle adulthood; one often noted personality change during middle adulthood is a gender crossover in personality.
6. Theory and research suggest that humans have the potential for continuous spiritual growth across the life course, with midlife adults having the capacity to recognize many truths and become more oriented to service to others.
7. The most central roles in middle adulthood are related to family and paid work.