For decades, genetic scientists have been investigating the genetic inheritance of intelligence, but with limited results. However, currently, genetic research has reached a stage where it can focus on genetic differences related to IQ with more power and precision.

Until five years ago, no genes had been associated with IQ test performance. Today, predictions are becoming more accurate, but further study is still needed to understand the impact of environmental factors on the development of intelligence.

The idea that DNA influences IQ, health, and behavior is known as “genetic determinism.” According to Harvard geneticist David Reich, the evidence is strengthening in favor of a genetic basis for intelligence. He questions, “Is performance on intelligence tests or the number of years of education someone receives shaped by upbringing? Certainly. However, does it measure something related to some aspect of behavior or cognition? Almost certainly. Given that all traits influenced by genetics are expected to vary between populations due to different frequencies of genetic variations, genetic influences on behavior and cognition will also vary between populations.”