Speaker Spotlight

Dr. Nancy L. Segal is unlocking the deepest mysteries of human nature through the most revealing lens science has to offer — twins. As Psychology Professor and Director of the Twin Studies Center at California State University, Fullerton, she has dedicated her career to understanding what makes us who we are—and her discoveries challenge everything we think we know about genetics, identity, and human connection.

Dr. Segal’s groundbreaking research has taken her from the laboratories of the University of Chicago, where she earned her Ph.D., to the most extraordinary twin stories on Earth. Her work on the landmark Minnesota Twin Study, chronicled in her award-winning book “Born Together-Reared Apart,” revealed how twins separated at birth and raised in different families can share uncanny similarities—from career choices to favorite foods to marriage patterns. This research earned her the American Psychological Association’s prestigious William James Book Award and fundamentally changed how we understand the interplay between nature and nurture.

But Dr. Segal’s investigations extend far beyond academic research into the most compelling human stories of our time. Her book “Deliberately Divided” exposed the controversial practice of deliberately separating twins for adoption studies, a story so powerful it became a 2022 BBC film. She documented the 40th anniversary reunion of Holocaust twin survivors at Auschwitz-Birkenau, capturing their resilience in “The Twin Children of the Holocaust.” Most recently, she chronicled a same-sex couple’s fight for their twin sons’ citizenship rights in “Gay Fathers, Twin Sons,” demonstrating how twin research intersects with social justice.

Dr. Segal’s work has captivated global audiences through her appearances on Oprah, Good Morning America, CNN, and NPR, and her research has been featured in The New York Times and Atlantic Monthly. Her latest project explores the extraordinary case of Colombian twins accidentally switched at birth—a story now streaming on Netflix as “The Accidental Twins.”

With over 300 scholarly articles, nine books, and recognition as the 2005 recipient of the James Shields Award for Lifetime Contributions to Twin Research, Dr. Segal continues to reveal how twins hold the key to understanding human potential, resilience, and the fundamental question of what makes each of us unique.