When I was younger, I read many books by Henri Laborit (https://en.wikipedia.org/wiki/Henri_Laborit) -- his work is predominantly in French. As a surgeon and neurobiologist, he wrote a lot about the biology of behaviour. I can't find the interview anymore, but during an interview (also in French) with a Canadian journalist he quipped this: "L'homme est un animal, le problème c'est qu'il parle." (roughly: "Man is an animal, the problem is that he uses language.") And, so, I agree with the essence of your position. But maybe the problem isn't that humans are surprised that other animals feeling/thinking. Rather the problem might be that humans think they actually aren't animals to begin with.