IQ Genetics Calculator
Estimate a child's IQ based on parental IQ using Galton's regression to the mean. Understand the role of genetics and environment in intelligence.
Parental IQ Input
Average
Average
Research suggests heritability is ~50% in childhood, ~60-80% in adulthood.
The Science of IQ Inheritance
Galton's Discovery
In the 1880s, Francis Galton discovered that children of exceptional parents tend to be less exceptional, while children of below-average parents tend to be less below-average. He called this "regression to mediocrity" (now called regression to the mean).
Twin Studies
Research on identical twins raised apart shows that IQ has a strong genetic component (50-80% heritability). However, heritability increases with age: children's IQ is more influenced by environment, while adult IQ is more influenced by genetics.
The Flynn Effect
IQ scores have risen about 3 points per decade throughout the 20th century. This shows that environmental factors (nutrition, education, familiarity with testing) can significantly impact IQ at a population level.
Frequently Asked Questions
Is IQ purely genetic?
No. While genetics play a significant role (50-80% heritability), environment, education, nutrition, and socioeconomic factors also substantially impact IQ.
Can two average IQ parents have a genius child?
Yes, but it's uncommon. Genetic recombination can produce children outside the expected range. The calculator shows probabilities, not certainties.
Why does IQ regress to the mean?
Extreme scores result from favorable combinations of many genetic and environmental factors. Children don't inherit all the same combinations, so scores tend toward average.
