One problem with twin studies is that the experiences of identical twins may be more similar than the experiences of fraternal twins, so that heredity appears to have a greater influence.

Question

Quizplus · Accepted Answer

Identical twins share 100% of their genetic material, while fraternal twins only share 50%. Therefore, if identical twins have more similar experiences, it may be difficult to determine whether their similarities are due to genes or environment.

One Problem with Twin Studies Is That the Experiences of Identical