Twin Studies

Definition

Twin studies are research designs used in psychology to measure the influence of genetic factors on human behavior by comparing identical (monozygotic) twins with fraternal (dizygotic) twins.

Related terms

Monozygotic Twins: Identical twins who develop from one zygote that splits into two embryos; they share 100% of their genes.

Dizygotic Twins: Also known as fraternal twins; they develop from two separate eggs fertilized by two separate sperm cells; they share about 50% of their genes just like any other siblings born separately.

Heredity: The genetic transmission of characteristics from parents to their offspring.