Cognitive ability stabilizes after age 3, study finds

Cognitive ability becomes stable after age 3, with weak links to infant measures, per PNAS study.

Why it matters

  • Cognitive ability impacts academic achievement, job performance, and health behaviors.
  • Understanding stability helps in early childhood development and education policies.

By the numbers

  • Sample size: 1,098 participants.
  • Correlation coefficients: ~0.16 and 0.18 for infant measures, 0.72 to 0.86 for ages 7+.
  • Genetic influence: 22% by age 3.
  • Environmental influence: 10% at ages 1-2.

The big picture

  • Cognitive ability is stable from age 3 onwards.
  • Early genetic and environmental factors play a role in adult cognitive ability.
  • Infant cognition measures are weak predictors of adult cognitive ability.

What they're saying

  • Comments show interest in environmental impacts before age 3.
  • Some humor about adults having the mental age of 3.

Caveats

  • Participants were all from Colorado, so results may not generalize.
  • Infant cognition measures are less reliable than those for older ages.

What’s next

  • Further research could look at different populations and cultures.
  • More studies on the impact of early environment on lifelong cognitive ability.