http://www.clickersolutions.com/articles/2001/macho.htm
This will be a two part post as it will not let me do it whole.
The Macho Myth
The social structure of domestic dogs is often described in terms of a linear dominance hierarchy, in which the top dog, or 'alpha animal', is dominant over all lower ranking animals, the second ranking dog is subordinate to the top dog but dominant over all others, and so on down to the lowest dog on the totem pole. Also, it is popularly believed:
Rank is established and maintained by physical strength and dominance.
The more dominant (i.e., higher ranking) dogs are more aggressive.
The most dominant dog is the most aggressive. Hence, dogs which frequently threaten, growl, fight and bite are often assumed to be 'alpha' animals.
The majority of the above assumptions are quite awry. Not only do they betray a theoretically simplistic view of a most sophisticated social structure but also, such notions tend to be counterproductive, inhumane and dangerous when cavalierly extrapolated to dog training, or the treatment of behavior problems.
Social Rank and Aggressiveness
It is generally assumed that high rank is correlated with aggressive behavior. In reality, a growly, macho top dog is a rare find. Top dogs rarely growl - they seldom need to! The true top dog is usually a cool customer, which is secure and confident of its privileged position and has no need to fluster and bluster to bolster up its rank. In the words of psychologist Dr. Linda Carlson, "If you've got it, there's no need to flaunt it." A true top dog is more likely to share a toy, a bone, or a sleeping place, than fight over one. On the other hand, bottom-ranking dogs rarely growl either. The prime directive of a low ranking individual is to maintain a low profile. Barking, growling and snarling only draw unwanted attention and if it came to a fight, the underdog would most certainly lose.
A top dog has little need to threaten and an underdog would be crazy to. Without a doubt excessive growling and repeated fighting is indicative of underlying insecurity and uncertainty about social rank vis a vis other dogs. Within a social group, protracted, blustery displays of aggression are the hallmark of the middle-order of the hierarchy. Middle-ranking dogs, threaten more and fight more frequently than higher- or lower-ranking individuals. With the advent of a litter on the social scene, it is not uncommon for a previously wimpy-wormy underdog to become ultra-macho with the puppies. Whilst maintaining its lowest of low profiles with other adults, the ex-underdog may wield its newfound power with exaggerated swagger: relentlessly hassling the developing puppies and adolescents (especially the males) by staring, stalking, dogging (following), barking and growling. Once an underdog assumes responsibility as a rearguard, the other adult males seldom bother with the (soon to be adult) youngsters and often the social atmosphere in the pack becomes more relaxed.
Subordinance Hierarchy
When the framework of a successful hierarchy is viewed in a developmental context, it becomes apparent that 'subordinance hierarchy' is a more descriptive term for canine social structure. This premise was first suggested by English primatologist Dr. Thelma Rowell. Maintenance of an existing hierarchy depends on the underlings respect of the position of higher-ranking individuals. The status quo is maintained because, lower-ranking individuals seldom challenge authority and so only occasionally, is there need to enforce higher rank with a display of physical, or more likely, psychological dominance.
Development of Hierarchies
Growing up around larger pups, adolescents and adult dogs, puppies simply can not compete on the social scene in view of their smaller size and inferior physical and psychological strength. Thus, puppies learn their station in life well before they become sufficiently large and strong to be a threat to the established order. Most adult dogs are quite lenient with young pups until they approach adolescence, whereupon adults (males especially) relentlessly pursue, stand-over and growl at the adolescents (males especially). Even so, harassment by adult dogs is largely psychological, rather than physical. It would be a perversely under-socialized adult dog, which physically beats up young puppies.
Nonetheless, during this crucial stage in hierarchical development, young pup and adolescents are extremely intimidated by the incessant harassment and consequently, they learn to respond with exaggerated appeasement gestures to assuage the torment from their elders. Moreover, puppies and adolescents quickly learn that bother from older dogs may be largely prevented by taking the initiative and demonstrating active appeasement before they are harassed. The pups' preemptive apology characteristically comprises: a low slung, wiggly approach with ears back, submissive grin and tail and hindquarters all a wag. The youngster may paw the brisket and lick the muzzle of the older dog. (The infantile pawing and muzzle-licking food-soliciting behaviors of puppyhood now acquire new meaning and are retained as neotenic appeasement gestures in adolescence and adulthood.) In addition, the underdog may rollover and lift a leg to expose its inguinal region. And some may submissively urinate. (Adult dogs may determine the age of a puppy or adolescent from the smell of the youngster's urine.)
From this stage on, to maintain harmony on the social scene, higher ranking dogs need only chastise those individuals which do not voluntarily show deference and respect in their presence. And even this is usually done with nothing more than a cold, penetrating stare.