> He asked what color he was, and learned "grey" after being told the answer six times. This made him the first and only non-human animal to have ever asked an existential question.
There's a little evidence[1] to suggest that the influence of a sentient (or intelligent) species can, to some degree, rub off. You could definitely cherry-pick specific traits of any species that would imply that it is not intellectual, including humans (e.g. war, intolerance). Maybe dogs don't have an intellectual reason for looking at us but that's not conclusive as to the intellectual capacity of the species.
At the end of the day I think it's inconceivable for a person to form an emotional bond with an animal such as a baboon - yet we do that with dogs and that's got to mean something, even if it's not scientifically quantifiable.
For an example, some dogs prefer to chase an object, but dogs bred for hunting might prefer carrying over chasing.
This makes a difference if you want to reward them, for the chasing dog you should throw the ball, but for the carrying of the object you should just give them the ball and let them walk around with it.
When you have determined what type of reward that work with your dog, your training become very effective.
When my 5 month old labrador rolls her ball under the couch (again), she tries for 5 seconds to get it herself, after that, she starts staring at me.
When she needs to "go", she will sit by the door and start staring at me.
Both of which are events that are not rewarded by food, but something she will enjoy by herself. (playing with a ball, and "relief"), even though in the latter case, I am very pleases she is going outside :).