JakeS:

So, a linearization, essentially...

Dimension reduction - find a conveniently small subset of linear combinations of the mass of observed variables which captures a suitably large fraction of the total variance.

Why do those seem to keep popping up in social, political and economic studies?

Because linear algebra is the only thing we humans know how to work with...

Most economists teach a theoretical framework that has been shown to be fundamentally useless. -- James K. Galbraith