Lots of ordinary people are into sex with a dash of voyeurism, fetishism and masochism - all habits classified as deviant in the manual doctors use to diagnose mental health disorders, a survey of Quebec residents suggests.

Researchers focused on what the manual calls paraphilic disorders - sexual behaviors labeled as abnormal, illegal or inducing suffering or impairment - and so-called normophilic, or typical, activities.

Most people have probably never heard of the guidebook in question, the Diagnostic and Statistical Manual of Mental Disorders (DSM).

But this book that once called homosexuality a deviant act can still help create and reinforce negative stereotypes for perfectly healthy sexual behavior, said lead study author Christian Joyal, a psychology researcher at the University of Quebec Trois-Rivieres.

"The adjective `abnormal' is judgmental," Joyal said by email. "I don't think it should appear in a psychiatry manual."

"Paraphilic disorders are rare because people who practice kinky or atypical sex are virtually all happy with it," Joyal added.

Researchers surveyed 1,040 adults in Quebec to see how often they desired or practiced eight sexual behaviors defined as outside the norm in the manual - fetishizing objects, wearing clothes from the opposite sex, spying on strangers, displaying genitals to unsuspecting strangers, rubbing against a stranger, pedophilia, masochism and sadism.

Overall, almost half of the respondents expressed interest in at least one of these eight sexual behaviors that the manual labels as deviant, researchers reported in the Journal of Sexual Research.

Roughly one third of the people surveyed said they had experienced one of these behaviors at least once, the survey found.

Participants either practiced or fantasized about four behaviors so often that it's difficult to consider them outside the norm, the authors point out.

Slightly more than one third of people were interested in voyeurism, while 26 percent expressed interest in fetishism or rubbing up against strangers, and 19 percent liked masochism, the survey found.

People interested in submissive sex were also significantly likely to be interested in a more diverse variety of sexual activities, the study found.

One limitation of the study is that people who respond to sex surveys may be more open-minded in their thinking about sexual behavior than individuals who decline to participate, the authors note. It's also possible that the online survey drew respondents who are not representative of the broader population.

Even so, the research is part of a growing body of work focused on debunking outdated social and psychological assumptions about sexuality, said researcher David Ley, author of The Myth of Sex Addiction.

"For years, the field of mental health believed masturbation and homosexuality were unhealthy, and that interest in fetish was statistically rare and usually unhealthy," Ley, who wasn't involved in the study, said by email. "It turns out we've been wrong on all counts."

It's possible that mental health providers look at common sexual behaviors as abnormal because they tend to see a rare subset of people who have problems related to their sexuality, Ley added.

"It's tragic that so many people are unnecessarily shamed about their sexualities, because it is such a core part of our human experience and identity," said Michael Aaron, a sex therapist in New York City who wasn't involved in the study.

"This shame permeates society, even down to the level of mental health and medical providers, most of whom have never had any sexuality training at all," Aaron added. "As long as the sexual behaviors are consensual and coming from a place of intentionality, they are healthy, but often people get the wrong idea from authority figures that should know better, but don't."