Although it can be stressful at first, indulging in sadomasochistic (S&M) activities is proven to improve relationship between consenting couples.

In a study of 13 men and women who were at an S&M party in Arizona, Brad Sagarin from Northern Illinois University in DeKalb found that although the levels of stress hormone, cortisol, rose significantly in those receiving the stimulation, the levels dropped back to normal within 40 minutes if the scene went well.

In another event, testosterone level was also measured in 45 men and women at an S&M event in Colorado and showed that it increased profoundly in receiving women only. In both studies, couples who said the party went well reported relationship closeness to their partners.

Nick Neave, a psychologist at the University of Northumbria, UK, says that it is important that future studies control whether paticipants experienced orgasm, which is associated with reduced stress and an increase in hormones associated with partner- bonding and affection.