there is a lot of studies in that topic. Even wikipedia agrees: >Early twin studies of adult individuals have found a heritability of IQ between 57% and 73%,[6

there is a lot of studies in that topic. Even wikipedia agrees: >Early twin studies of adult individuals have found a heritability of IQ between 57% and 73%,[6] with some recent studies showing heritability for IQ as high as 80%.[7] IQ goes from being weakly correlated with genetics for children, to being strongly correlated with genetics for late teens and adults. The heritability of IQ increases with the child's age and reaches a plateau at 18–20 years old, continuing at that level well into adulthood. However, poor prenatal environment, malnutrition and disease are known to have lifelong deleterious effects.[8][9][10]