What Twins Can Tell Us About Who We Are

In December 1988, two sets of identical twins in Bogotá became test subjects in a study for which they had never volunteered. It was an experiment that could never be performed in a lab, and had never before been documented. And it became a testament to the eternal tug between nature and nurture in shaping who we are.

This week, psychologist Nancy Segal tells the story of the Bogotá twins, which was a tragedy, a soap opera, and a science experiment, all rolled into one. And she explains why twin studies aren't just for twins. They can serve as a paradigm to understand age-old questions that affect us all: Is our fate written in our genes? And how powerful is upbringing in shaping who we become?

Insights — and provocations — from twin studies, this week on Hidden Brain.

Additional Resources:

"Accidental Brothers: The Story of Twins Exchanged at Birth and the Power of Nature and Nurture," by Nancy Segal and Yesika Montoya, 2018

"Pairs of Genetically Unrelated Look-Alikes: Further Tests of Personality Similarity and Social Affiliation," by Nancy Segal and colleagues, 2018

"Socioeconomic Status Modifies Heritability of IQ in Young Children," by Eric Turkheimer and colleagues, 2003

"Personality Similarity in Twins Reared Apart and Together," by Thomas Bouchard and colleagues, 1988

Hidden Brain is hosted by Shankar Vedantam and produced by Jennifer Schmidt, Parth Shah, Rhaina Cohen, Laura Kwerel, and Thomas Lu. Our supervising producer is Tara Boyle. You can also follow us on Twitter @hiddenbrain, and listen for Hidden Brain stories each week on your local public radio station. [Copyright 2019 NPR]