The social unit of dogs is the pack. From research on wolf packs that are formed in captivity, the pack has traditionally been thought of as a tightly knit group composed of individuals that have earned a ranking in a linear hierarchy, and within which there is intense loyalty. It is believed that dogs were able to be domesticated by and succeed in contact with human society because of their social nature. According to this traditional belief, dogs generalize their social instincts to include humans, in essence “joining the pack” of their owner/handler.
However, much of this traditional view is based on findings from grey wolf packs that are formed of unrelated animals in captivity, and thus may not apply to natural wolf packs, natural dog packs, or dogs incorporated into a human household. Research in packs formed in the wild indicates that wolves form a family group, including a breeding pair and their offspring. In these familial packs, the terms “dominance,” and “submission” are less useful than “parent,” and “offspring,” and bring with them a number of misconceptions. While the majority of research to date indicates that domestic dogs conform to a hierarchy around an Alpha-Beta-Omega structure, domestic dogs, like their wild wolf counterparts, also interact in complex hierarchical ways.
The existence and nature of personality traits in dogs have been studied (15,329 dogs of 164 different breeds) and five consistent and stable “narrow traits” identified, described as playfulness, curiosity/fearlessness, chase-proneness, sociability and aggressiveness.
Clearly, sociability is the trait that has been selectively bred for many generations so our domestic dogs tend to come ‘hard-wired’ with this predisposition toward loyalty to their human companions.