It’s a phrase that has firmly ensconced itself in popular language, particularly when talking about parenting. But where did the idea of “nature vs. nurture” come from? The answer is the now infamous Minnesota Study of Twins Reared Apart (MISTRA).

In this study, researchers focused on the tale of identical twins who were separated at birth and adopted by different families. It wasn’t until they were 39 that they met, and they were surprised to find they both suffered headaches, bit their nails, smoked Salems, took up woodworking and even vacationed on the same beach in Florida. In fact, their adoptive families also coincidentally named each twin Jim.

Nancy L. Segal, who spent nearly a decade working on the Minnesota Study, has just authored “Born Together—Reared Apart: The Landmark Minnesota Twin Study.” What unique perspective does Segal bring to this old debate? How important are genetics in the way a child turns out? Not all identical twins are as similar in personality and habits as the two Jims, so what explains those common themes when they weren’t even nurtured in the same way? Does it have to be nature or nurture? Can’t it be both?

Guest:

Nancy Segal, Author of Born Together—Reared Apart: The Landmark Minnesota Twin Study (Harvard University Press); Distinguished Professor in Humanities and Social Sciences and Director of the Twin Studies Center at California State University, Fullerton