What is a good iq score by age?
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Understanding Good IQ Scores by Age
Introduction to IQ Scores and Age
IQ, or Intelligence Quotient, is a measure of a person's cognitive abilities in relation to their age group. It is often used to predict educational and occupational outcomes, as well as to identify potential cognitive delays in children. Understanding what constitutes a "good" IQ score can vary depending on the age of the individual and the context in which the IQ is being assessed.
Predictive Value of Early Childhood IQ Scores
Ages 3 to 6 Years
Research has shown that IQ scores assessed at an early age can be predictive of later cognitive abilities. For instance, a study using the Ages and Stages Questionnaire (ASQ) at 36 months found that it could effectively predict IQ scores at ages 5 to 6 years. Children with an ASQ score below 270 at 36 months were more likely to have an IQ below 85 at ages 5 to 6 years. This suggests that early developmental assessments can be crucial in identifying children at risk for cognitive delays.
Stability of IQ in Young Children
In young autistic children, IQ scores assessed between ages 2 to 7 years were found to be quite stable and predictive of later IQ scores, especially when the same test was used at both assessments. This stability indicates that early IQ assessments can provide reliable information about future cognitive abilities.
IQ Scores in Adolescence and Adulthood
Predictive Power of Childhood IQ
IQ scores obtained in childhood have been shown to predict educational and occupational status in adulthood. By the second grade, the predictive correlations of childhood IQ with adult outcomes were nearly as strong as those obtained with contemporaneous adult IQ scores . This highlights the long-term significance of early IQ assessments.
Age-Related Changes in IQ
The Wechsler Abbreviated Scale of Intelligence-Second Edition (WASI-II) has demonstrated that certain cognitive abilities, such as vocabulary and similarities, are more resistant to aging, while others, like block design and matrix reasoning, show substantial declines with age. The Full Scale IQ remains relatively stable until around age 65, after which it begins to decline. This pattern is consistent with theories of crystallized and fluid intelligence, where crystallized intelligence (knowledge and skills) remains stable, and fluid intelligence (problem-solving and reasoning) declines with age.
Longitudinal Studies and IQ Stability
From Childhood to Adulthood
Longitudinal studies, such as the Munich Longitudinal Study on the Ontogenesis of Individual Competencies (LOGIC), have found that IQ stability is moderately high from preschool to early adulthood. Children with higher initial IQ scores tend to maintain their cognitive advantage over time and are more likely to pursue higher educational tracks. This underscores the importance of early cognitive development and its lasting impact.
The Flynn Effect and IQ Variability
The Flynn Effect, which refers to generational increases in IQ scores, has been observed to vary by age and ability level. For example, IQ scores increased by 2.3 points at age 13 but decreased by 1.6 points at age 18. Additionally, those with lower initial IQs (<70) experienced a decline, while those with higher IQs (>130) saw an increase. This variability suggests that the Flynn Effect is not uniform across all age groups and ability levels.
Conclusion
A "good" IQ score can vary significantly depending on the age of the individual and the context of the assessment. Early childhood IQ scores are predictive of later cognitive abilities and can help identify children at risk for cognitive delays. IQ stability tends to increase with age, and early cognitive advantages often persist into adulthood. Understanding these patterns can help educators, parents, and policymakers make informed decisions about early interventions and support for cognitive development.
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