Gestricius said:
How do heads of village/village elders get their authority in rural areas in the second and third world? Simply being the eldest and thereby considered the wisest or by some sort of inauguration?
It depends. In a lot of places it's sort of ad hoc and there can be more than one elder. Conversely I know that in parts of rural West Africa there is a specific designated elder with a costume and specific roles, and it's heriditary so nobody disputes it. They're a sort of final authority on local decisions (like a judge) but don't wield actual power, so it's not as attractive to power trippers.
From my observation lot of communities even in Europe and America have a "village elder" of sorts. This is usually the person most people point to when an outsider wants to know more about the history of the place and whatnot. In my area there's this elderly energetic guy with a garden and he knows everyone, so he's been "democratically" chosen as the local representative by people acknowledging him as such.