Saw a show the other night comparing them with dogs. Big difference is that even wolves raised in captivity from birth, by strong instinct, fear humans.
If you have any interest in wolves (within driving distance to Lancaster County, PA) the sanctuary at Speedwell is a great place to visit. Beautiful animals. Went this past February for the first time. Cooler months are best times to visit, they're very active - I would not want to go there mid-summer.