The Twin Study

The Twin Study is a research method that compares identical (monozygotic) and fraternal (dizygotic) twins to understand the roles of genetics and environment in human traits. Since identical twins share nearly 100% of their genes, differences between them can highlight environmental influences, while similarities suggest genetic factors. Conversely, fraternal twins share about half their genes, providing a different comparison. These studies help researchers determine how much genetics contribute to traits like intelligence, personality, and health, by analyzing patterns of similarities and differences among twins raised together or apart.