Religious cults have not been very successful in recruiting and keeping members in recent years, a Virginia sociology professor told a Southern Baptist conference here last week.

David Bromley, chairman of the department of sociology and anthropology at Virginia Commonwealth University in Richmond, estimated that there are fewer than 25,000 members of all cult groups combined in the United States.

He told a conference sponsored by the interfaith witness department of the Southern Baptist Home Mission Board that it is a myth that cults brainwash their converts.

"If they could brainwash people," he said, "you would assume their success rate for recruitment would be very high, and that the escape and defection rate would be very low."

Bromley, a coauthor of the 1981 book, "Strange Gods: The Great American Cult Scare," said there were never more than 7,500 members of the Unification Church at its peak, and that now there are probably fewer than 3,500.

He said the controversial church recruits only about 100 converts each year.

The sociologist estimated that the defection rate among cults ranges from 20 percent to 50 percent each year. He said one reason for the defections is that most cults are plagued by schism and conflict.

Bromley warned against efforts to legalize deprogramming, the forcible removal of members of cults to try to get them to repudiate their beliefs.

He said that such laws, if passed, could be used against Baptists and people of other established religions, and that they are dangerous to society.