Timothy Jay gives a damn about cursing.
The 42-year-old psychology professor is the author of a new book called "Cursing in America" (John Benjamins, $14.95) which reveals what he has learned in 20 years of research on how and why people curse.
Boys, Mr. Jay discovered, curse more than girls beginning at age 5. Until then, the sexes are equally profane and equally ignorant of the meaning of the few profanities they utter.
Movies have gotten much bluer in language. This is no surprise, but Mr. Jay actually counted curse words in movies from different decades. It was light work from the 1940s through '50s, but by 1969, the year of "Midnight Cowboy," he needed a calculator. That Academy Award winner boasts 107 curse words.
"Cursing in America" is just reaching bookstores, but if interest from radio talk show hosts and their listeners is any indication, sales should be good.
Mr. Jay, who teaches at North Adams State College in North Adams, Mass., has been on about 50 radio talk show programs this month, and he has more scheduled.
"It's hit a nerve," he said in a telephone interview from his office in North Adams. "People ask me, 'Why are you interested in this?' 'Do you swear very much?' 'Are we getting more offensive, more vulgar?' Those are all real good questions."
Mr. Jay insists that he doesn't swear very much. ("If I shut my finger in a door, I probably would swear. . . . I don't have the occasion or the anger to use this kind of language very much anymore.") He suspects, although there's no solid research to say for sure that cursing has become more common in the United States in recent years.
Among the findings in "Cursing":
* Curse words account for 8 percent of leisure conversation among college students and 13 percent of leisure conversation among adults.
* A male coach is the most likely campus worker to be heard cursing; a female librarian is the least likely.
* A male dorm is the most likely place on campus to hear cursing. A day-care center is the least. Other likely sites include the school newspaper office and gym. Unlikely sites include the piano lab and career planning office.
* Graffiti by females is less sexual than graffiti by males.