Here's an interesting map for you all to study [1] with more background explanations here [2]. But the clustering has some puzzling flaws: Cyprus is grouped with (unmarked) 'South Asian' (but given it's half-Turkish and half-Greek what would you group it with?); Malaysia, like Indonesia, is predominantly Islamic, so should be colored grey, not green; on the other hand, only 30% in Ethiopia is islamic, the large majority Christian [3] so it is better classified with the 'Africa' group; Germany has about 30% Cattholics and 30% Protestant [4] so the border between those groups should be drawn right through Germany; The Netherlands is predominantly non-religious, but the Catholic group is larger than the Protestant one so the colored border should be moved here, too. (1/2)