Nurture Takes the Spotlight

Decoding the environment's role in development and disease

Identical twin sisters Elizabeth and Eleanor (not their real names) say that when they entered the world on November 19, 1939—Elizabeth first, then Eleanor 8 minutes later—their mother was rather shocked. She’d been expecting just one baby, not two. But that day, she made a vow: The girls would always be treated the same, so that there would be no competition between them.