I’ve been studying tango for years, both because I love it and because of the lessons it keeps teaching me about emotional and physical connection in relationship. A few months ago, I had the opportunity to tango with an accomplished dancer who had exotic ways of moving his body and all kinds of frills in his technique. Initially, it was exciting, but I soon found myself feeling detached as his partner. Then I danced with a man who seemed much less technically skilled and couldn’t do anything close to the steps of the first man, but he engaged me as a partner in a completely different way. It was the difference between dancing in my own bubble and sharing a moment with someone else. With the first partner, I had to match his fancy performance moves, which, while varied and novel, quickly became emotionally predictable. But with the second, far less skilled partner, I never knew what was going to happen next because he was picking up from me as much as I was picking up from him. Any time I started to lose my balance just a little bit, I could feel him right there with me, and we readjusted. There was one move in which I had to step around him while we shaped our bodies together. By then, we’d established our connection and were completely in sync, attuned. It was such a thrill—and this is what gives tango that erotic edge.

I saw the same thing recently in the Netherlands watching two swans in a mating dance. There was this beautiful synchrony between them, as if they…