Hi! When I took animal behavior in college, the top rank was the dolphin and the pig. However, I have had dogs and horses that would differ with that statement. But again I agree the dolphin and pig are the smartest. Rabbits, are not that high on the intelligence rate simple because they are not domesticated to perform a job. Whether it is work related like a horse or mule, protection like a dog or friend. Rabbits just don't make the mental leap. However, that does not mean that they can not know how to be litter box trained, come when you call them and snuggle. My daughter had a rabbit that lived in her bedroom, was litter boxed trained in a week or so. Came when you called Zoe and stood up to the cats and dogs. In fact. I have pictures of them sleeping with her. So. my guess, is any animal that is loved, cared for and knows it, is smart. Maybe more then we will ever know. Just my humble opinion.
Accept if this helped you.