How are wolf packs actually structured?

The answer

The concept of the 'alpha wolf' dominating a pack through aggression was based on studies of unrelated captive wolves forced to live together. In the wild, wolf packs are actually family units consisting of a breeding pair (parents) and their offspring from multiple years. The original researcher, L. David Mech, has spent decades trying to correct this misconception. Pack dynamics are governed by family bonds rather than dominance hierarchies; the parents lead naturally, much as human parents lead their families. Older siblings help raise younger pups, and adolescent wolves typically disperse at 1-3 years of age to find mates and establish their own families. Cooperation, not aggression, is the defining feature of wolf social life.