I don't know about the Alpha, Beat, Gamma etc specifics, but there are certainly men and women who seem to naturally find a place in a social structure with one or more people who they instantly defer to. It might be hard to point one out in the media, as I guess you have to be a little more assertive and naturally charismatic to be there in the first place? But odds are good that, if you think about your social circles, you'll instantly be able to know who is sort of the "Central" person - The one who does things and invites other people to those things and when they aren't around the group feels a little lost.

For want of a better term, those people could be called an Alpha, while the others that naturally let them take control of the group are Betas. Thanks to a lot of this online chatter we kind of look down on the term "Beta" and think less of them, but that's sort of like thinking less of a Sargent because he isn't a Captain. Groups need different people to work, I think. Everyone brings something... Those who seem to be the centre of the group bring that energy, while others bring other things that makes a group work together.