Two Monozygotic Heads Are Better Than...
On Martha Stewart (video worth watching at link), my fascinating friend, professor Nancy Segal, the premier twin researcher, on her studies on twins, plus giving some very interesting answers to some interesting questions. It's such a treat to hear Nancy talk about her research -- she came to an LA dinner of evolutionary psychologists I just arranged -- and now you can hear what she has to say as well. Even if you're not a twin, I think you'll find what she says very interesting. And even if you're not a twin, twin studies -- especially on monozygotic (identical) twins separated at birth -- can tell us a lot about ourselves, including teasing out information about nature/nurture.

Her recent book: Indivisible by Two: Lives of Extraordinary Twins

Her upcoming book: Someone Else's Twin: The True Story of Babies Switched at Birth

Her previous book: Entwined Lives: Twins and What They Tell Us About Human Behavior

An excerpt from Nancy's Psychology Today blog:

The reunion happened in Spain's Canary Islands. A thirty-five-year-old woman entered a shop and was greeted warmly by the assistant who believed she was her friend. But the assistant was rebuffed. The assistant later called her friend to follow up, only to learn that her friend had never been to the shop that day. The first woman returned several days later, and it was then that the assistant began to question her. A meeting was arranged--and it was clear that the two (the woman and the friend) were identical twins; this was later confirmed by DNA testing. To complicate things further, one of the women said that she had a twin sister, but that she was not identical. Eventually, it was established that one of the twins had been accidentally switched with a non-twin infant in the hospital's baby nursery. And it was disclosed that the identical twins had been conjoined and successfully separated, although the nature of their physical connection was not reported. Everyone's life was immeasurably altered by that chance recognition, and the various parties are suing the hospital for millions of dollars.

...Some people do not relish the idea of an identical other--and yet many people envy the closeness and intimacy that comes so naturally to most identical twins. A number of the reunited twins in our study had initial concerns about loss of identity or sense of self, but their worries faded fast once they got to know one another. As investigators, we were impressed with how similar the reared apart identical twins were, but it was never perfect similarity. It also surprises me that most identical twins think that they do not look alike--and yet many must if mistaken identity can bring some together.

A story about reunited separated twins who were torn apart (as part of a horrible study). Via NPR, from a story by Joe Richman:

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. Both women were 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.

Now, the twins, authors of a new memoir called Identical Strangers, are trying to uncover the truth about the study.

...Peter Neubauer, a child psychiatrist, and Viola Bernard, a child psychologist and consultant to the Louise Wise agency, headed up the study.

Lawrence Perlman, a research assistant on the study from 1968 to 1969, says Bernard had a strong belief that twins should be raised separately.

"That twins were often dressed the same and treated exactly the same, she felt, interfered with their independent psychological development," Perlman says.

Lawrence Wright is the author of Twins, a book about twin studies.

"Since the beginning of science, twins have offered a unique opportunity to study to what extent nature vs. nurture influences the way we develop, the people that we turn out to be," Wright says.

Wright notes that the Neubauer study differs from all other twin studies in that it followed the twins from infancy.

"From a scientific point of view, it's beautiful. It's practically the perfect study. But this study would never happen today," Wright says.

Nancy Segal does the other kind of research, the ethical kind.