What do identical twins tell us about nature vs. nurture?

Please direct all requests for permission to photocopy or reproduce article content through the University of California Press's Rights and Permissions website, at ... traditional twin studies. Scholars have long studied twins to address the nature- nurture question. read more

as do any two full siblings. Comparing identical and frater-nal twins enables researchers to separate genetic from envi-ronmental influences without measuring genes directly. If a physical or behavioral trait, like hair color or success at math, is shared more often by identical twins than by fra-ternal twins, researchers reason, genes must have played a role in developing the trait. read more

Critics note that identical twins tend to be treated more alike than fraternal twins and suspect that this greater environmental similarity may explain the greater trait similarity of identical twins. For example, identical twins are probably more often dressed alike than fraternal twins. read more

The 50-year old twins have more epigenetic tags in different places than do 3-year-old twins. The insight we gain from studying twins helps us to better understand how nature and nurture work together. read more