ABSTRACT
Despite the tremendous progress in the field of genetics over the past several decades, gaps in knowledge regarding the genetic influences underlying executive functions (EF) remain immensely wide. Twin studies have largely confirmed that genetic influences play a crucial role in contributing to individual differences in EF across development, but molecular genetic studies have to uncover the specific genes that make up this variation. There is consensus that genetic influences play an important role in just about every psychological trait, including EF. One way of discerning the heritability of a trait is through the classic twin study. The twin study methodology is described elsewhere, but the basic premise is summarized. The twin study involves trait comparisons between monozygotic (MZ) and dizygotic twins. Given that MZ twins share 100% of their genes, trait differences within MZ twin-pairs are assumed to be due to environmental factors.
