Do animals have complex emotions

I've heard some debate about this over the years. Some say yes and some say no. I'm not sure how you would go about measuring or verifying this. I can tell you that I believe they do because of the experiences I've had with my two dogs over the last 12 years. They may not reason the way we do but they do have emotion. The degree to which they experience those emotions may vary from species to species. In short, I don't "know," but I think so.

It depends on which animal you are talking about. Many highly evolved mammals do have complex emotions. On the other end, there are animals that do not have any at all.