Why enemies, or love-hate relationships, are so bad for your health

When I look at the members of my social network, I am mostly filled with feelings of unadulterated love and warmth: I simply cannot wait to see them again, knowing that we will enjoy each other’s affection and support.

A handful, however, arouse very different emotions: a mixture of eagerness and fear. They promise encounters that are the conversational equivalent of Russian roulette. In the right frame of mind, these people can provide a fun evening, but if I rob them at the wrong moment, they can drain me of all my good will. You just never know what’s coming.

If this sounds familiar, you have enemies too. Psychologists call them “ambivalent relationships,” and not only do they have the potential to ruin a good party, they also have surprising consequences for your well-being. According to a wealth of research, these love-hate relationships tend to be more stressful than interactions with people who are consistently unpleasant. They can damage your physical and mental health. They may also be aging you prematurely.

Knowing this, the simple solution would seem to be to cut ties with these people. But our relations with enemies are not simple, and abandoning them is not always possible or even desirable. However, a deeper insight into your ambivalent relationships will help you deal with them more effectively. It could also make you a better friend. Because when you know the signs to look out for, you may find that the enemy in some of your relationships is you.

Since the 1970s, large studies examining…