Does your iq change as you get older
Pro Research Analysisby 
Searched over 200M research papers
Consensus Meter
Does Your IQ Change as You Get Older?
Age-Related Changes in IQ
Decline in Cognitive Abilities with Age
Research indicates that IQ tends to decline with age, but the pattern of decline varies between different types of cognitive abilities. Performance IQ, which involves problem-solving and processing speed, tends to decline earlier and more rapidly, while verbal IQ, which involves language and comprehension, declines later and more slowly. This pattern has been observed in the general population, suggesting that aging impacts different cognitive domains in distinct ways.
Stability of IQ in Healthy Older Adults
Contrary to the general trend of cognitive decline, some studies have found that IQ remains relatively stable in healthy older adults. For instance, a longitudinal study of 231 older adults over four years found that while there were significant decreases in brain volumes, verbal and non-verbal IQ measures remained stable. This suggests that neuroanatomical changes do not necessarily translate to immediate cognitive deterioration in healthy individuals.
The Wilson Effect: Heritability of IQ
The heritability of IQ appears to increase with age, reaching a peak in late adolescence and remaining high into adulthood. This phenomenon, known as the Wilson Effect, indicates that genetic factors play a more significant role in determining IQ as individuals age, while the influence of shared environmental factors diminishes. This underscores the complex interplay between genetics and environment in cognitive aging.
Factors Influencing IQ Changes
Cognitive Reserve and Terminal Decline
The cognitive reserve hypothesis posits that individuals with higher IQs can better tolerate age-related brain pathologies, delaying the onset of terminal cognitive decline. However, once decline begins, it tends to be steeper in individuals with higher initial IQs. This suggests that while a higher IQ may offer some protection against early cognitive decline, it does not prevent it entirely.
Impact of Early Life IQ on Later Life
Longitudinal studies have shown that higher IQ scores in childhood are associated with lower mortality rates and better health outcomes in later life. This relationship highlights the long-term benefits of higher cognitive abilities established early in life, which may contribute to a more resilient aging process.
Education and Cognitive Aging
Education has been found to positively influence IQ in later life, particularly for individuals with lower initial IQ scores. However, education does not appear to significantly impact cognitive processing speed, which is a fundamental aspect of cognitive function. This suggests that while education can enhance certain cognitive capacities, it may not affect all aspects of cognitive aging equally.
Neuroanatomical Correlates of IQ Changes
Brain Structure and IQ
Changes in brain structure, such as cortical thickness and surface area, have been linked to IQ. More intelligent children tend to have a thinner cortex, which thins more rapidly over time. In contrast, in more intelligent adults, a thicker cortex is associated with higher IQ. These findings suggest that the relationship between brain structure and intelligence is dynamic and evolves with age.
Brain Aging and Cognitive Function
Despite age-related declines in brain volumes, studies have not found strong evidence linking these changes to simultaneous cognitive deterioration. For example, decreases in grey matter and white matter volumes were observed without corresponding declines in IQ measures. This indicates that the brain may have compensatory mechanisms that help maintain cognitive function despite structural changes.
Conclusion
In summary, while IQ does tend to decline with age, the extent and pattern of this decline can vary based on several factors, including the type of cognitive ability, genetic influences, early life IQ, and education. Neuroanatomical changes also play a role, but their impact on cognitive function is not straightforward. Understanding these dynamics can help in developing strategies to maintain cognitive health in aging populations.
Sources and full results
Most relevant research papers on this topic