Written by the Fiveable Content Team • Last updated August 2025
Verified for the 2026 exam
Verified for the 2026 exam•Written by the Fiveable Content Team • Last updated August 2025
Definition
Identical twins are siblings who develop from a single fertilized egg that splits into two. They share the same genetic makeup and are often used in studies to investigate the influence of nature versus nurture.
Nature vs. Nurture: This term refers to the debate about whether genetics (nature) or environmental factors (nurture) have a greater impact on human development.