When relationship researchers gathered recently for their big international conference, one presentation drew a lot of attention because it offered an answer to a question often asked but rarely examined: Can sexual fantasies improve your relationship?

The answer: Yes—as long as you are fantasizing about your partner.

Previous research shows that just about everyone—between 95% to 98% of the population—has sexual fantasies. Not everyone, of course, wants to act on them. In general, men’s fantasies are more sexually explicit. They are more likely to fantasize about multiple partners, some studies found. Women’s fantasies contain more romantic and emotional content.

“Fantasies reflect how we cope with our insecurities and whether we want to promote intimacy or escape from it,” says Gurit Birnbaum, a social psychologist and associate professor of psychology at the Interdisciplinary Center, a private university in Herzliya, Israel, who is the lead researcher on the new studies. “Tell me your fantasies and I will tell you what your personality is and what you want out of your relationship.”

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A study published in the January, 2015, issue of the Journal of Sexual Medicine found typical types of fantasies for both men and women include feeling romantic emotions during sex, imagining a particular atmosphere and location, receiving oral sex and (particularly for men) having sexual intercourse with two women.

What people fantasize about is determined by a number of factors, experts say, including hormones, age, past sexual experiences, relationship length and satisfaction level, personality and even emotional attachment style. People who avoid emotional attachment—psychologists call this having a highly avoidant attachment style—typically fantasize about casual, nonemotional sex. People with a highly anxious attachment style, who crave emotional attachment and worry they will lose the person they love, are more likely to fantasize about pleasing their partner. People with a secure attachment style are most likely to fantasize about romantic, loving sex.

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