Cognitive ability (probably) peaks between 50 and 60
4 days ago
- #intelligence
- #aging
- #cognitive-decline
- Intelligence test scores show different trajectories for fluid and crystalized intelligence after age 20.
- Fluid intelligence (problem-solving without prior knowledge) declines after age 20, while crystalized intelligence (using learned information) remains stable or increases until later in life.
- Cross-sectional studies may be biased by the Flynn effect, which shows IQ improvements over generations, complicating age-related decline assessments.
- Longitudinal studies suggest intelligence increases until at least age 50, with significant declines only after age 60 or 70.
- Practice effects in longitudinal studies may inflate IQ scores over time, but adjustments suggest minimal impact on overall trends.
- Quasi-longitudinal studies indicate slower declines in reasoning (fluid intelligence) and stable or slightly increasing vocabulary (crystalized intelligence) with age.
- Measurement invariance tests support the reliability of longitudinal data, showing consistent cognitive ability patterns across different testing waves.
- The distinction between fluid and crystalized intelligence in aging research may be overstated, as both show similar patterns of increase and decline.