Is IQ solely determined by genetics?

IQ is not solely determined by genetics; environmental factors also play a significant role. Dwarkesh Patel discussed the influence of both genetics and upbringing on IQ, referencing studies on identical twins raised in different environments. These studies show that while there is a strong genetic component, as evidenced by a high correlation in IQ between twins (around 0.8), the environment can still significantly influence IQ outcomes. Furthermore, evidence from twin studies shows that even when twins are raised apart in different cultural and familial contexts, their IQs tend to be very similar, supporting the idea that genetics plays a substantial role, but it is not exclusive[1].

Additionally, Dwarkesh Patel noted correlations between brain features and IQ, such as skull size, although these do not account for all variations in intelligence, suggesting that both genetic background and environmental factors are important[1].