Dr. Nan­cy L. Segal is Psy­chol­o­gy Pro­fes­sor and Direc­tor, Twin Stud­ies Cen­ter, at Cal­i­for­nia State Uni­ver­si­ty, Fuller­ton. Her 2021 book, Born Togeth­er-Reared Apart, won the Amer­i­can Psy­cho­log­i­cal Asso­ci­a­tion’s William James Book Award. Her work has been fea­tured in The New York Times and The Atlantic. She has appeared on the Oprah Win­frey Show, Good Morn­ing Amer­i­ca, and the BBC.