Can your iq change over time
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Can Your IQ Change Over Time?
Stability and Change in IQ Over the Lifespan
Early Childhood to Adulthood
Research indicates that IQ can exhibit both stability and change over the lifespan. A longitudinal study tracking individuals from early childhood to early adulthood found that while general intelligence remains moderately stable, the degree of stability increases with age and is higher for shorter intervals between assessments. Interestingly, children with initially higher IQs tend to maintain their advantage over time, whereas those with lower IQs show greater stability in their scores.
Teenage Years
During the teenage years, IQ can fluctuate significantly. Studies using neuroimaging have shown that both verbal and non-verbal IQs can rise or fall during adolescence. These changes are closely linked to structural changes in the brain, such as variations in grey matter in regions associated with speech and motor skills. This suggests that intellectual capacity relative to peers can change during these formative years, offering hope for improvement and a caution for early achievers.
The Flynn Effect
The Flynn Effect, which describes generational increases in IQ scores, shows that IQ can change over time on a population level. However, this effect is not uniform across all ages and ability levels. For instance, while younger adolescents may show an increase in IQ, older adolescents and those with lower initial IQs may experience a decline. This variability challenges the notion of a consistent upward trend in IQ across all demographics .
IQ Changes in Special Populations
Individuals with Intellectual Disabilities
In populations with intellectual disabilities, the pattern of IQ change differs from the general population. Studies indicate that verbal abilities tend to decline more rapidly than performance abilities in these groups. This contrasts with the general population, where performance IQ declines earlier and more rapidly than verbal IQ.
Schizophrenia
For individuals with schizophrenia, IQ tends to increase at a slower rate compared to healthy individuals. This slower increase is attributed to a lack of practice effects, which are more pronounced in healthy subjects. Consequently, schizophrenia is characterized by a relative lack of gain in global cognitive abilities over time.
Factors Influencing IQ Changes
Education
Education has a significant impact on IQ, particularly in later life. Higher levels of education are associated with higher IQ scores in older age, especially for individuals with lower initial IQs. However, education does not appear to improve fundamental cognitive processing speeds, such as reaction time.
Brain Structure
Changes in brain structure, such as cortical thickness and surface area, are also related to IQ changes. More intelligent children tend to have a thinner cortex, which thins more rapidly over time. In contrast, cortical surface area expands during adolescence and then decreases, with more intelligent individuals completing this expansion earlier. These structural changes suggest that intelligence is closely linked to the timing and magnitude of brain development.
Cognitive Reserve
The concept of cognitive reserve posits that individuals with higher IQs can better tolerate age-related brain changes, delaying the onset of cognitive decline. However, once decline begins, it tends to be steeper in those with higher IQs. This phenomenon supports the idea that higher initial cognitive abilities can buffer against early decline but do not prevent it entirely.
Conclusion
In summary, IQ is not a static measure and can change over time due to various factors, including age, brain development, education, and health conditions. While some aspects of IQ remain stable, significant fluctuations can occur, particularly during adolescence and in special populations. Understanding these dynamics can help in developing strategies to support cognitive development and mitigate decline across the lifespan.
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