Once upon a time, Greece was an intellectual hotbed. Greeks created philosophies that are still part of our civilization millenia later. Greeks also laid the basis for a number of key intellectual disciplines that are still vibrant and critical to our technology today. Yet modern Greece is basically a third world nation that’s lucky to be in Europe so they can leech off the EU.
Could it be that it was the rise of Hellenistic civilization that doomed Greece? Before that, great thinkers had to, for the most part, stay in Greece. Afterward the spread of Hellenistic culture over the Mediterranean basin, an upwardly mobile Greek could prosper in a large geographic region as well (or potentially more) as they could in Greece. It seems that this would lead to a large “brain drain” as we term it in the current era. The population of Greece during that era wasn’t all that large so it wouldn’t take a particularly massive population movement to have a big effect. Moreover, the era in question lasted for centuries, starting with Alexander the Great and lasting until at least the collapse of the Western Roman Empire. After this last event, no more is heard of Greece with regard to intellectual developments (one source refers to Proclus, who lived around 450 AD, as “the last major Greek philosopher”). Was Greece done in by the mass emigration of leading lights? Or do other cultural shifts explain the demise of world class thought in Greece? I favor the former but I’m sure it could be argued strongly both ways. And one must keep in mind that there are positive and negative feeback loops between nature and nuture, especially for entire populations. (An alternative is the Silicon Valley hypothesis, which is that a critical mass of thinkers is required to produce significant achievements and the exodus of thinkers during Hellenistic times dropped Greece below the threshold).
Still, it does seems a cautionary tale about sustained emmigration.