From Abigail Curtis:
I did my science fair project on learning by observation when I was in the fifth grade. We put eight ponies in a ring, tied up so that they could all see what the pony in the middle was doing. Before we brought them in we had put a treat under a bucket on a chair. Then we let one of the ponies, go and timed how long it was before the pony found the treat. The first timing was about 2 minutes (it was so long ago that I have a hard time remembering exactly what the timing was). When we let the next pony go the time was much shorter (about 30 seconds). After that all the other ponies ran straight to the chair when we let them go.
Then, just for kicks, we brought in six more ponies and this time showed them where we were putting the treat, and they all ran straight for the bucket. This experiment has made me greatly disbeleive any people who say that horses don't learn from observation.
We had also created monster ponies. By letting them find a treat on a chair ONCE, they now knock over and chew on any chair that they see, so that also proves how fast they learn, and how long they remember things (always important to remember in training)
Karen Pryor comments: A primatologist and a psychologist working together recently made headlines by demonstrating that chimpanzees could watch a person indicating the location of a hidden treat, but could not then find the treat. Dogs, however, could easily read such human clues as glances, pointing, and looking, and could easily find the indicated hiding place. The conclusion was that dogs, through their long association with humans, have learned to read our body language pretty well, but chimpanzees, though they are primates like us, can't do that.
I have always thought that horses were good at learning by observation (and I have a large collection of examples now) because they need to watch and copy each other in the wild. Maybe, however, as domestic animals they are also rather good at watching us and understanding what we are doing, especially if it's something useful to them. Food for thought.