Can iq decrease with age

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Research Analysis by Consensus

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Yes20%

Possibly80%

No0%

Can IQ Decrease with Age?

Age-Related Decline in IQ

Research consistently shows that IQ can decline with age, though the pattern of decline varies between different types of cognitive abilities. Longitudinal studies indicate that performance IQ tends to decline early and rapidly, while verbal IQ declines later and more slowly. This pattern is observed in the general population and is influenced by various factors, including health and lifestyle.

Impact of Aging on Cognitive Performance

Studies examining the effects of aging on cognitive performance reveal that older adults experience declines in various cognitive tasks. For instance, in tasks involving numerosity discrimination, recognition memory, and lexical decision, older adults showed significant declines in performance compared to younger individuals. However, these declines were not significantly different between individuals with low and high IQs. This suggests that while aging affects cognitive performance, the extent of decline may not be heavily influenced by baseline IQ levels.

Cognitive Reserve and Terminal Decline

The concept of cognitive reserve posits that individuals with higher IQs can better tolerate age-related brain pathologies, delaying the onset of terminal decline (TD). However, once TD begins, the rate of decline is steeper in individuals with higher IQs compared to those with lower IQs. This has been observed in cognitive tests of perceptual and motor speed, spatial, and verbal abilities. Thus, while higher IQ may delay cognitive decline, it does not prevent it.

Influence of Early Life IQ on Later Cognitive Decline

Premorbid IQ, or IQ measured in early life, has been linked to cognitive outcomes in later life. Studies show that higher early-life IQ is associated with lower mortality rates and better cognitive function in middle and late adulthood. However, the influence of early-life IQ on cognitive decline varies, with some studies indicating that the effect size decreases from childhood into young adulthood.

Fluid Intelligence and Aging

Fluid intelligence, which involves the ability to reason and solve new problems, also declines with age. Research using Raven's Progressive Matrices, a measure of fluid intelligence, found that fluid IQ decreases annually in older adults. This decline is influenced by both age and practice effects, with initial improvements due to practice followed by a steady decline. The Flynn Effect, which describes generational increases in IQ, does not uniformly apply to all age groups, with some older adults showing a reverse Flynn Effect, indicating a decrease in IQ over time.

Conclusion

In summary, IQ does decline with age, with performance IQ declining earlier and more rapidly than verbal IQ. While higher IQ may provide some cognitive reserve, delaying the onset of terminal decline, it does not prevent the eventual decline in cognitive abilities. Early-life IQ has a lasting impact on cognitive outcomes, but its influence diminishes over time. Understanding these patterns can help in developing strategies to mitigate cognitive decline in aging populations.