Conducted at the University of Colorado Boulder with over 1,000 twins, the study found that simple tests performed in infancy could predict cognitive abilities at age 30.
Researchers linked infants' reactions at 7 months old—such as interest in new toys or attention span—with intelligence test results years later.
The study identified behaviors like "interest in novelty" and "task focus" as the strongest indicators of cognitive performance in later years. This long-term twin research proved that both genetics and environment play roles in intelligence development.
While genetic influence increases as children grow, the study revealed that environmental effects during the first one or two years have a lasting 10% impact on adult intelligence.
Additionally, the research tested a "polygenic intelligence score" based on individuals' DNA. This score summarizes the influence of thousands of genetic variants into a single number that reflects genetic intelligence propensity.
The study found a striking correlation between infancy test results and these genetic scores.
