Among many packs of wild animals, a certain structure is formed that involves one leader, a few higher-up "officers", the general population of varying mid-range status, and a few "underdogs" at the bottom. Many lycanthrope packs have adopted the same structure, albeit with a clear definition of which individuals are "alphas" (thus the leader and officers) and which are not. Backing up this structure is that there does actually seem to be two different "species" of lycanthrope for each critter-type, one being rarer (about 10%-15% of the population) and more preternaturally boosted than the other. These are commonly called "alpha shifters". Although they are not innately better leaders in any sense, they certainly seem to have the tools to establish dominance by way of threat and brute force, as well as relying on the common tradition of "might makes right" among were-things.
About the only clear difference between a standard shifter's range of preternatural abilities and an alpha shifter's is that alphas more often have the ability to shift select parts of their bodies than a standard shifter does, as well as the ability to force others to shift (or not shift) against their instinct or wishes. They also show a natural aptitude in Dominating others, Healing themselves, resisting accidental shifting under duress, and occasionally they do not follow the standard expectations for how hard-hit they are by silver or silvered objects.
For the most part, that's about the only difference between alpha shapeshifters and "normal" shifters (if one will forgive the contradiction in terms) — although many of the alphas like to claim that they are the natural leaders and the primary force behind the lycanthropic population (as is evidenced by them calling themselves "Alpha" shifters) and that without them, their packs would dissolve and be ursurped, this is largely a propagandist smear-campaign intended to keep the standard shifter from running amok and giving shapeshifters a bad name. There is actually no connection between leadership qualities nor self-control nor self-reliance and if a shifter is an alpha or not, if the shifter is kept from being influenced by peer-pressure.
As such, many preterologists theorize that "alpha" shifters might be comparable to a genetic accident, like being born albino or with more than five fingers per hand, and are thus deviations from the standard "true" lycanthrope template. This theory is further backed up by the fact that directly cursed individuals (and thus supposedly closer to the source) generally do not ever exhibit "alpha-like" powers. Obviously, due to the self-claimed attitude, temper, and ego of many alpha shifters, such theories are not widely discussed.