Comment by brap

I had a dog when I was younger that was from a dog sled line but was many generations removed from pulling sleds. She seemed to love to pull on stuff, ropes, leashes, toys, people holding her, or whatever else, so we bought a dog harness and attached a garden wagon to her a few years in. And she was absolutely obsessed with pulling it around and seemed like she would have happily run herself to death pulling it around if we let her. The harder you tried to hold the wagon, the harder she would pull and the more fun she seemed to be having.

It is just anecdotal, but I 100% believe there was nothing she found more entertaining and fun than to pull that wagon because of her genetics. There was no training involved, within seconds of hooking her up with a harness she just knew what she had to do.

We got a purebred Aussie sheepdog (kelpie) that failed its tests at a year old. They were going to shoot her, so she became our family pet.

She was obsessed with rounding things up - cats, ducks, kids, you name it.

Part of her dna for sure.

It's pretty hard to avoid any situations where pulling is possible. Such as on leash. You usually have to intensely train working dogs not to pull on leash.

They would still fixate on other behaviors they are trained on. And if not trained and neglected, often have destructive behaviors.

Just a guess but I would imagine the behavior is deeply instinctive by this point.