Sounds like a self-proclaimed dog trainer on another forum I'm on. "That behavior can't exist because it goes against nature and survival." The funny part is, the person owns a Siberian Husky; I don't recall hearing about any packs of wild dogs willingly tethering themselves to heavy objects, with or without other animals, and freighting them around. And yet, humans have somehow managed to breed dogs that not only do it, but enjoy every moment of it, and some will even overexert themselves to death if given half a chance. For the same reason some dogs genuinely enjoy fighting: we bred them to essentially be adrenaline junkies, and it's self-rewarding.
Erm.. nearly all athletes, wrestlers, cage fighters, drunk idiots at the bar..
not to mention S&M :rofl1: