“Several decades of evidence show that when it comes to both your happiness and your physical health, frenemies are actually worse than enemies. … Ambivalent relationships where you have mixed feelings toward other people are actually worse for your well-being because they're unpredictable. You don't know whether Dr. Jekyll or Mr. Hyde is going to show up. You don't know whether you should move in for a hug or brace yourself for a brawl.”

…that when it comes to both your happiness and your physical health, frenemies are actually worse than enemies. And I think a lot of people find this surprising. They think, you know, the most toxic person in your life has to be somebody who's always an adversary and who's constantly putting you down and badmouthing you behind your back and undermining you. But what the research shows is that ambivalent relationships where you have mixed feelings toward other people are actually worse for your well-being because they're unpredictable. You don't know whether Dr. Jekyll or Mr. Hyde is going to show up. You don't know whether you should move in for a hug or brace yourself for a brawl. I think people have this all the time with their in-laws. They belittle your parenting, but they're also really good to your kids. And so how should you feel about them? You don't know. You spend all this time and energy trying to predict what's going to happen and to resolve your uncertainty about it. And that can actually take a toll physiologically. There are experiments where people are…