I was reading an article the other day that talked about people's facial expressions and their emotions. The article said that when people get angry or negative, that their pupils will constrict and contract. I went and looked at pictures of my uBPDm, and in every picture that's close up enough to see it, her pupils are constricted really small. I haven't seen my uBPDm in years, but it would be an interesting thing to take a look at. It might have some value in predicting a rage coming on.
