Source: Pressmaster/Shutterstock

Imagine yourself in this scenario: you are in a long-term relationship, and one day you discover that your partner is pursuing a relationship with someone else. How would you feel?

Many of us would experience , an unpleasant sensation that can motivate behavior designed to reduce the risk of our loved one leaving us for someone new. These behaviors can be positive, such as redoubling efforts to be a good partner, but are all too often negative, and can include emotional or physical abuse directed at the partner or a rival.

However, some readers may have a different answer. Perhaps you wouldn’t feel jealousy, but rather compersion.

What is compersion? It’s the feeling of warmth or joy we experience when we imagine or know that our partner is emotionally or sexually involved with another person.

And if you have never heard of compersion, or think the chances of feeling warmth or joy if your partner were to hook up with someone else are slim to none, you are probably not in a consensually non-monogamous relationship.

There are various types of consensually non-monogamous relationships. Some people identify as , or as swingers, or are in open relationships. What these people have in common is a belief that relationships with a third person are not necessarily wrong and, in fact, may even be a positive experience. Hence, compersion: “I don’t feel jealous that you are in a relationship with another person; on the contrary, I’m happy for you.”

Compersion is not as well understood by psychologists as jealousy, which is why a number of researchers have begun studying this topic in recent years. Among those researchers are Justin Mogilski and his colleagues at Oakland University in Michigan.

For a study currently in press at the journal Archives of Sexual Behavior, Mogilski recruited several hundred male and female volunteers who reported that they were involved in either a monogamous or a consensually non-monogamous relationship, and had these volunteers complete surveys about their relationships.

He found that monogamous people reported greater emotional distress than consensually non-monogamous people at the prospect of their partner being involved with another person. This makes sense: Consensually non-monogamous people, by definition, should be OK with their partner playing away from home.

Still, many people in non-monogamous relationships have rules about when it is permissible to enter into a relationship with a third-party, and so it is still possible to cheat in a non-monogamous relationship. This perhaps explains why Mogilski’s consensually non-monogamous volunteers thought about their partners’ extra-pair relationships more than his monogamous partners did—a greater opportunity to stray may produce more food for thought.

Mogilski also found that, far from being blissfully free of jealousy, consensually non-monogamous people were less confident than their monogamous peers that their partners would never cheat on them.

The ideal polyamorous relationship may be egalitarian and non-hierarchical, but in reality, it is not unusual for a person to have a primary and a secondary partner. Consensually non-monogamous people tend to think it is more important that their primary partner remains faithful: A cheating secondary partner is less unappealing.

Monogamous people mate-guard their partners more than the consensually non-monogamous, who in turn guard their primary partner more than their secondary partner.

Selfish or Selfless?

Mogilski asked his volunteers whether they would find pleasure—a jolt of compersion—if their partners became involved with another person. Even monogamous people indicated this would sometimes be true, although women reported that they would find greater enjoyment if their partner had with someone else, and men if their partner fell in love with someone else.

However, previous research has also shown that women find a partner’s emotional more distressing, while men find a partner’s sexual infidelity more distressing. It could be that Mogilski’s results do not reflect compersion so much as a lack of distress: Just because a woman is more disturbed by the prospect of an emotionally unfaithful partner doesn’t mean that she will be overjoyed beyond rapture if her partner is sexually unfaithful.

Mogilski suggests an alternative explanation. Perhaps compersion has a selfish component. A person with a desire for sexual novelty may be persuaded to remain in a primary relationship if their partner consents to non- . Similarly, bringing a third partner into the mix may benefit both members of the original couple, especially if they are non-heterosexual.

All of this is not to say that the consensually non-monogamous do not genuinely feel compersion. But to conceptualize compersion as the opposite of jealousy is probably not useful.

Instead, Mogilski suggests, it may be better to think of it as “the satisfaction of provisioning a desirable resource to a valuable mate.” If both original partners benefit from the arrangement, “compersion may be easier to experience.”