According to Guns, Germs, and Steel which societies that had agriculture as their principal source of calories developed into political...

When you say "political structure societies," I assume
that you are talking about what Diamond calls (in Chapter 14) chiefdoms or states. 
Diamond states that only societies that have agriculture can advance to either of these
two stages.  However, not all agricultural societies make it.  Diamond says that there
are two ways that small agricultural societies can become
bigger.

First, they can merge because they have to merge in
order to keep from being conquered.  This would be, for example, a case in which two
smaller societies merged so that they would be able to fight against a larger neighbor. 
Second, a small society can simply be conquered by a larger one and become part of that
larger society.

So, the societies that develop into
"political structure" societies are the ones that are threatened from the outside and
have to either join with other small societies or be conquered by the outside
threat.