The Internet was supposed to let us bridge continents and cultures like never before. But after analyzing more than 10 million e-mails from Yahoo! mail, a team of computer researchers noticed an interesting phenomenon: E-mails tend to flow much more frequently between countries with certain economic and cultural similarities.

Among the factors that matter are GDP, trade, language, non-Commonwealth colonial relations, and a couple of academic-sounding cultural metrics, like power-distance, individualism, masculinity and uncertainty. (More on those later.)

The findings were released in a paper titled The Mesh of Civilizations and International Email Flows, written by researchers at Stanford, Cornell, Yahoo! and Qatar's Computational Research Institute.