What Fraction of the Variation Among IQ Scores is Attributable

Question

What fraction of the variation among IQ scores is attributable to genetic differences among people?
A) 0.1
B) 0.3
C) 0.5
D) 0.7
E) 0.9

Accepted Answer

The most commonly cited estimate is that genetic factors account for approximately 50% of the variation in IQ scores among individuals. Therefore, choice C (0.5) is the correct answer. The other choices are incorrect as they do not accurately represent the percentage of variation in IQ scores that is due to genetic differences.