The results of the study point to marked differences between how men and women interpret sexual fantasies.
The researchers behind the study - from the Institut universitaire en santé mentale de Montréal and Institut Philippe-Pinel de Montréal, both affiliated with the University of Montreal, Canada - say that existing scientific literature on paraphilias, or atypical fantasies, does not define what these types of fantasies actually consist of.
The fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) - the handbook of psychologists in North America - refers only to "anomalous" fantasies, and the World Health Organization (WHO) is similarly vague, referring to "unusual" fantasies when defining paraphilias.
"Clinically, we know what pathological sexual fantasies are: they involve non-consenting partners, they induce pain, or they are absolutely necessary in deriving satisfaction," says lead author Christian Joyal. "But apart from that, what exactly are abnormal or atypical fantasies?"
Joyal and colleagues conducted a survey among the general population to find out. The participants in the survey were 799 men and 718 women from Quebec with a mean age of 30 years. The respondents were required to describe their sexual fantasies in a questionnaire and to describe their favorite fantasy in detail.
Surprisingly few fantasies are 'rare,' statistically
The survey shows that the nature of sexual fantasies are very varied among the general population, with surprisingly few fantasies actually being statistically "rare," "unusual" or "typical."
The researchers give examples of "rare" fantasies as scenarios that might involve sex with a child or animal, "unusual" fantasies as those that might involve urination, cross-dressing, sex with prostitutes or abusing an intoxicated person, while "typical" fantasies might be those that involve sex in a romantic location, receiving oral sex or - for men - having sex with two women.
The study also confirms the sexual stereotype of men having more fantasies, and describing them more vividly, than women.
In addition, the results point to marked differences between how men and women interpret sexual fantasies.
For instance, although 30-60% of women detailed fantasies that involved submissive themes - the researchers give the examples of being tied up, spanked or forced to have sex - the survey found that women were much less likely to want to act their fantasy out in real life than men. The majority of men said that they would love their fantasies to come true.
Joyal comments on this finding:
"Overall, these findings allow us to shed light on certain social phenomena, such as the popularity of the book Fifty Shades of Grey with women.
The subject is fascinating. We are currently conducting statistical analyses with the same data to demonstrate the existence of homogeneous subgroups of individuals based on combinations of fantasies. For example, people who have submission fantasies also often report domination fantasies. These two themes are, therefore, not exclusive, quite the contrary. They also seem associated with a higher level of satisfaction."
Women also reported that they fantasize more about their partner than men do. Men reported fantasizing much more about extramarital relationships, compared with women.
Joyal says that one of the most intriguing findings of the study related to the significant number of fantasies that were uniquely male - "for example, regarding shemales, anal sex among heterosexuals, and the idea of watching their partner have sex with another man."
"Evolutionary biological theories cannot explain these fantasies," Joyal claims. Joyal, unfortunately, does not qualify his use of the problematic term "shemale" - traditionally used in the pornography industry as a derogatory term for transgender women. For instance, in this context, is "shemale" used deliberately to evoke a porn-filtered view of straight male fantasies involving transgendered people?
Male and female paraphilias and problematic sexual power dynamics
The debate over what is a "normal" or "unusual" sexual fantasy has received fierce media attention this week, as the Canadian broadcaster Jian Ghomeshi has been the subject of claims from eight women who allege that he performed violent and sadistic sexual acts on them without consent.
A previous study found that women who have read Fifty Shades of Grey are more likely to have abusive partners.
Although none of the allegations have - as yet - been reported to the police, Ghomeshi's employer, the public-funded broadcasting corporation CBC, fired the radio host over the claims.
Ghomeshi - who has not denied the details of the encounters, but claims that they were consensual - has responded with a $55 million lawsuit for defamation and breach of trust, in which he suggests that CBC fired him over a "moral judgement" that his practice of a bondage-domination-sadomasochism (BDSM) sex life was wrong.
The case is relevant to the new study as it has opened a debate across the media over the differences between male and female fantasies - some of the women, for instance, say they shared submissive fantasies with Ghomeshi but did not consent to him acting them out.
Perhaps one of the most intriguing comments on the case came from a friend of Ghomeshi's, the Canadian musician Owen Pallett, who launched a petition to show support for the women who - six anonymously - have brought forward allegations:
"The beauty of BDSM relationships is that the power is always in the hands of the [submissive partner]," Pallett opined. "BDSM and choke play is a subversion of male violence."
If the acts were non-consensual, Pallett says that "abusing the BDSM power relationship for the purpose of engaging in non-consensual violence against women is horrifying. That is not the point of BDSM. BDSM is, in fact, about the exact opposite thing. It is about repurposing acts of violence into creating a power dynamic of [...] equality."
Although Pallett's comments posit BDSM as a "subversion" of male sexual violence, another study recently reported on by Medical News Today found that women who have read the BDSM-themed erotic fiction of Fifty Shades of Grey are more likely to have abusive partners.
That study found that Fifty Shades readers were 25% more likely to have a partner who verbally abused them, 34% more likely to have a partner who showed stalking tendencies, and 75% more likely to have starved themselves for more than 24 hours.