I'd never thought about placebo's being a social mechanism. As a bit of a tangent, one of things I've always wondered is "how much pain do animals feel compare

I'd never thought about placebo's being a social mechanism. As a bit of a tangent, one of things I've always wondered is "how much pain do animals feel compared to humans?" The null hypothesis here would be that they feel the same amount, of course. On the other hand, what's an animal going to do with joint pain? Humans are unique in our ability to perform interventions. Suppose two people have cancer, one shows symptoms and one does not. A tumor can be excised before it becomes malignant. One would live and the other would die. Is there a pressure on us to have pain so that we can seek treatment? To bring this around to your comment. I wonder if we've demonstrated placebo effects on animals. That seems like an awfully hard study to conduct.