What is it that makes us who we really are: our life experiences or our DNA? Paula Bernstein and Elyse Schein were both born in New York City, adopted as infants, and raised by loving families. They met for the first time when they were 35 years old and found they were “identical strangers.”

Unknowingly, Bernstein and Schein had been part of a secret research project in the 1960s and ’70s that separated identical twins as infants and followed their development in a one-of-a-kind experiment to assess the influence of nature vs. nurture in child development. This documentary includes the first tape ever broadcast of Dr. Peter Neubauer, who headed the study, describing his secret experiment.