"First of all, I would say that she's not a psychologist," Gilligan says. "Second, what's her study?"

Indeed, only a select few have seen the interview transcripts that Gilligan interpreted when writing In a Different Voice.

Gilligan says she only gives researchers access to the transcripts if they have what she deems a legitimate research goal.

This includes, according to Gilligan, "20 to 30" dissertations and theses based on the work, and a few other published studies by colleagues.

Most of these studies confirm her findings, Gilligan says.

But Debra Nails, now an associate professor of philosophy at Mary Washington College, wrote in a 1983 Social Research article that Gilligan gave her access to some of her interview transcripts--and she found Gilligan's extrapolations highly subjective. "However prettily the literary criticism disguises itself as science, one cannot trust its conclusions," Nails wrote. "This type of research is social science at sea without an anchor."

John M. Broughton, an associate professor of psychology and education at Columbia and former Gilligan colleague, helped compile the raw data for In a Different Voice. He subsequently wrote a scholarly article finding fault with the book's conclusions.