Paula S
They do exist it wolf packs, although they are a lot less common then in dogs, and usually to a lesser degree. This is how trouble makers get kicked out, usually to come back in a couple weeks, or they will join a neighboring pack. (as a follower, not a leader)
Humans do create a lot more unstable betas, yes vaccines and other medical problems create a large amount, but also in play is the human pack and lifestyle. They don't have anyone more qualifiyed to take the lead position, so the dog does, and the insecurity of being placed in a position where they are not qualified (and they know it) leads them to bully behaviour and other odd behaviour.
Each animal (wolf or dog . . .or human) has their own degree of one of these three main personalities, how much they show depends on individual, health, lifestyle, how they were raised, and how they are currently raised, diet, and I'm sure several other factors.
It's a good article for showing humans the real qualities of an alpha, patience is huge on the list, as is an air of authority (not authoritarian), and following through on a rule breach. Respect is huge in a healthy pack, and it goes both ways, creating resentment in a group where you each depend on each other is usually not a good thing.
I would say that it is probably 90% human created, and 10% instinct. It could be even more. :)