I think it's a pendulum. I remember when no scientist would say in print that animals could experience pain, and my shock when first reading a peer-reviewed art

I think it's a pendulum. I remember when no scientist would say in print that animals could experience pain, and my shock when first reading a peer-reviewed article that suggested that (fish I think it was) did. Back then the Nim experiments were held to show that animals were not capable of understanding language in any way ('cause their syntax was imperfect.) However, before that scientists had been too quick to trumpet any sign of symbolic understanding as "animals understanding language." Of course, it is also strict traditional (Thomist) Catholic doctrine that animals do not have souls (the seat of experience) or go to heaven; go back far enough and that was a strong limit on what science it was easy to publish.