Many years ago I subscribed to New Scientist, which in those days had a page or two of short science news items near the front of every issue. One of those items caught my attention at once and has stayed with me ever since. As I remember it, this is how it went:
Unequal societies may arise naturally
A small computer modelling research team [names] reports [journal name] that just one or two very simple rules are enough to mimic the evolution of an egalitarian society into a profoundly unequal one.