The Palmieri Hypothesis was a sociological theory posited by Professor Palmieri in the late 23rd or early 24th century. It stemmed from flaws Palmieri perceived in Hodgkin's Law of Parallel Planetary Development, and by the late 24th century, it was the more generally accepted of the two theories of how similar cultures arise on different planets. (SCE eBook: Fables of the Prime Directive)

The story never explains exactly what Palmieri's hypothesis says or how it differs from Hodgkin's Law.