The real reason humans are so obsessed with sex: It helps pair-bonding in a relationship

Representational image. AFP[/caption]Sex is important for pair-bonding between men and women in relationships and not just mere waste of energy, the study said."The function of sex in humans outside ovulation is an evolutionary mystery. But we believe that it has to do with binding the parties in the relationship together," said Leif Edward Ottesen Kennair, Professor of psychology at Norwegian University of Science and Technology.The researchers also found that commitment in a relationship and the type of oral contraceptive women use are linked to how often couples have sex.For the study, researchers asked hundreds of Norwegian heterosexual women about contraception, sex and relationships.The results showed that of women in long-term relationships and who are using hormonal contraception, those who are more committed to their relationships have more sex with partners."But this association was especially true when the contraceptive that women used had potent levels of synthetic hormones that mimic the effects of the natural hormone progesterone, and lower levels of the hormone estrogen," Steve Gangestad, Professor at the University of New Mexico.The findings were published in the journal Evolution and Human Behavior.