By Chapter II of Jack London's novel The Call of the Wild, the narrator and protagonist Buck makes it very clear that the domesticated dogs he came into contact with once having arrived in Alaska are behaving like wolves due to their violence. He witnesses dogs' faces being torn off by other dogs and dogs being killed by a pack of dogs, just like a wolf pack will move in for a kill. As Buck phrases it, "He had never seen dogs fight as these wolfish creatures fought," but his observations also taught him valuable lessons about survival.
In contrast, unlike we might expect of wolves, some of the dogs are capable of showing kindness. One example can be seen in Buck's teammate Billee, whom Buck describes as having an "excessive good nature." On Buck's first night out in the cold wilderness, he didn't understand how to keep warm. He was chased out of the tent. Not knowing what to do, he circled round and round the campsite, shivering, trying to find warmth and wondering where his other teammates were. As he circled, he was startled when the snow beneath his feet moved. Billee gave a "friendly little yelp," licked Buck's face, and essentially showed him how to keep warm by burying himself in the snow. We might assume that wolves wouldn't show so much kindness. We also might assume that wolves are not as fast at learning as Buck.