Harvard professor rarely join families torn by incest, wives who hate their mothers-in-law and women who love Michael Bolton on the Oprah Winfrey Show.

But the Medical School's John E. Mack is one of the few.

Mack, a psychiatrist, leaped onto the daytime TV scene and into the pages of Newsweek, the Boston Globe and Time after he authored a book entitled "Abduction: Human Encounters With Aliens," which claims that UFOs really do exist and kidnap humans.

And with Mack's Harvard affiliation and Pulitzer Prize, won in 1977 for a biography of T.E. Lawrence, his book hardly seems likely fodder for Oprah.

Its contents, however are. The book suggests that people around the nation have had alien abduction experiences.

Many of these people claim to have encountered small, hairless, large-eyed gray creatures, which kidnapped them and in many cases stole sperm and egg samples. The book, published last April, focuses on 13 specific alleged alien encounters.

Mack says although he himself has never encountered an alien, the interviews he did for the book convinced him of their existence.

"Ninety people have had these experiences and they were very powerful for them," Mack says "I can't find any explanation for this."

Similar reports of abduction by aliens have come from sane, rational individuals from across the nation who have not had contact with each other, Mack says.

"This occurs in people who do not have psychological illnesses and have nothing to gain by it," Mack says. "It even occurs in kids less than three years old, which rules out a complicated personality theory."

Evidence also includes physical marks on the bodies of experiencers, and the common phenomenon of people who awake upside down in bed.

"Mack's work is extraordinarily legitimate," says Rudy Schields, a friend of Mack's and an astrophysicist at the Harvard Smithsonian Center for Astrophysics.

"His approach is as accurate as anything in the behavioral sciences. His methods and procedures are as good as anybody's," Schields says.

Unorthodox Conclusions

But Mack's unorthodox conclusions are, not surprisingly, far from universally accepted.