While men spend more time thinking about sex than their partners overall, a survey found that women have more fantasies which could be described as “pleasant”.
Men, on the other hand, are more likely to occupy their minds with wilder and more exploratory ideas such as “swinging” with other couples or taking part in an orgy, researchers found.
Women more frequently imagined being forced into submission in a sexual scenario — but they also took less enjoyment from the idea than men.
Nieves Moyano Muñoz, who led the study, said: “These fantasies are not very frequent but compared with men, women have more. But they experience it in a more negative way.”
The researchers, from the University of Granada, questioned 2,250 Spanish people who had been in a heterosexual relationship for at least six months about the frequency and nature of their sexual thoughts.
Their results, published in the Anales de Psicología journal, showed that almost all participants had experienced a pleasant sexual fantasy at some point in their life, and 80 per cent had also had a negative one.
The team said there were not “significant” differences between men’s and women’s racy thoughts, but that there were subtle differences between the sexes in the scenarios that they imagined.
Although men had more sexual fantasies in total, women reported having “pleasant” fantasies “a few” times a month — a greater frequency than men.
Men were more likely to admit having either positive or negative thoughts about experimental activities, such as “being promiscuous”, “being a swinger” or “participating in an orgy”, although most said that they only had such fantasies once a year or at some point in their life.
Ms Muñoz added: “These are not very frequently experienced — in normal life men and women have very similar fantasies. They have this type of fantasy about one or two times in their whole life.”
Sexual submission was the least enjoyable fantasy among women, with most imagining it at least once in their life, while for men the most negative thoughts involved homosexual activities.
The survey was aimed at helping determine whether unpleasant fantasies harm the development of healthy sexual behaviour.
Researchers pointed out that imagining sex could be helpful in some ways, for example by encouraging sexual desire or arousal.
They suggested that therapists should not only ask whether or not people have fantasies about sex, but also consider their attitude towards them.