And empathy has two qualities: One is the understanding part of it. This is just a regular definition: the ability to understand and share the feelings of another. And the emotional part. Empathy has basically two channels: One is the body channel, if you talk with a sad person, you're going to adopt a sad expression and a sad posture, and before you know it, you feel sad. And that's sort of the body channel of emotional empathy, which many animals have. Your average dog has that also. That's why people keep mammals in the home and not turtles or snakes or something like that, who don't have that kind of empathy. And then there's a cognitive channel, which is more that you can take the perspective of somebody else. And that's more limited. Very few animals, I think elephants and apes, can do that kind of thing. So synchronization, which is part of that whole empathy mechanism, is a very old one in the animal kingdom.