Human Growth and Development / Unit 18 HGD 2590 review, 2 to 3 minutes
Does Intelligence Decline With Age?
The idea
The last arc ends on a question the exam often asks. Cross-sectional studies once suggested steep intellectual decline with age, but they confused age with cohort. The Seattle Longitudinal Study, entry 1823, following the same people since nineteen fifty-six, found verbal memory, spatial skills, inductive reasoning and vocabulary rising into the seventies, while numerical computation and perceptual speed declined. Fluid intelligence does fall in late life, and crystallized intelligence holds or rises, entry 2130, with the two changing together in each person. Denney's model, entry 1825, adds that practice and education raise the level a person reaches, so decline starts from a higher point. The "use it or lose it" hypothesis, entry 2157, holds that some decline reflects disuse. Training helps the trained skills: in the ACTIVE trial, entry 2158, reasoning and speed effects lasted ten years, while memory effects faded. Whether brain games prevent dementia remains inconclusive, entry 1826.
In practice
Two eighty-year-olds, one who stopped reading and socializing at retirement and one who kept learning languages, each compared with a younger self rather than with today's students.
Where people slip
The misconception is that intelligence declines across the board with age. Some abilities decline, some hold and some grow, and much of the apparent decline in older studies came from comparing different generations. Unit one's point about research design is the key: cross-sectional comparisons confound age with cohort, and longitudinal designs follow the same people. For the exam, know the fluid and crystallized pattern, the Seattle study's findings, and why longitudinal and cross-sectional results differ. Age brings losses and gains together, and the balance differs from person to person, as entry 2130 found. That pattern closes the intelligence arc and the course.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
Builds on
Unlocks
- Nothing yet depends on this.
Something wrong in this lesson? Flag it · Sources for Human Growth and Development