Dr. Peter Neubauer
The minds behind the study were Dr. Peter Neubauer and his colleague Dr. Viola Bernard. They headed a study at Manhattan’s Child Development Center in the 1950s and 60s that aimed to study the nature versus nurture debate. Neubauer, a Freudian psychiatrist, and Bernard, and psychologist got their subjects for the study from the now-closed Louise Wise Services adoption agency in New York City.
Source: Boredom Therapy
It’s not really clear exactly how many sets of twins they observed, but there were at least 13 children; 5 sets of twins and one set on triplets (Bobby, Eddy, and David) were officially on the record.