Chapter 21 Summary

1. It was traditionally assumed that intelligence was one general entity. From that assumption sprung the idea that intelligence in a measurable quantity, which decreases over adulthood. However, current evidence questions these assumptions.
2. Longitudinal research has found that the IQ of each adult tends to increase, particularly in vocabulary and general knowledge, until age 60 or so. Cross-sectional research has found that the reason younger adults traditionally score higher than older adults on IQ tests is not because of their age but because of historical improvements in health and education.
3. K. Warner Schaie found that some primary abilities (such as spatial understanding) decline with age while others (such as vocabulary) increase. Education, vocation, and family, as well as age, seem to affect these abilities.

4. Cattell and Horn concluded that although crystallized intelligence—which is based on accumulated knowledge—increases over time, a person’s fluid, flexible reasoning skills decline with age.
5. Sternberg proposed three fundamental forms of intelligence: analytic, creative, and practical. Most research finds that, although analytic and creative abilities decline with age, practical intelligence may improve.
6. Overall, cultural values and the changing demands that come with age develop some cognitive abilities more than others. Each person and each culture responds to these demands, but their influence on cognition may not be reflected in psychometric tests.

7. People experience many stressors over the 40+ years of adulthood, and they use various coping methods, depending on the particular stressor and on their age and background. A combination of stressors increases allostatic load and reduces health.
8. As people grow older, they choose to focus on certain aspects of their lives, optimizing development in those areas and compensating for declines in others, as necessary. As applied to cognition, selective optimization with compensation means that people specialize in whatever intellectual skills they choose. Meanwhile, abilities that are not exercised may fade.
9. In addition to being more experienced, experts are better thinkers than novices for four reasons. They are more intuitive; their cognitive processes are automatic, often seeming to require little conscious thought; they use more and better strategies to perform whatever task is required; they are more flexible.
10. Expertise in adulthood is particularly apparent in the workplace, as evidenced by doctors, airplane pilots, and taxi drivers. Experienced workers often outperform younger workers because they specialize, compensating for any losses that may appear.
11. Raising children and responding well to the emotional complexities and unanticipated challenges of family life are now recognized and valued as expert work. Experience and maturation increase the likelihood of family expertise.