coif

In response to the mandate (which may or may not be true, despite what the computer says) for all North Korean males to model their hair-style after their Supreme Leader, Bob Canada points out that having one, utilitarian and uniform hair-cut, on a planetary-scale did not seem to detract from the success of the Vulcans, so maybe it is not such a bad idea.  I suppose the Romulan and the Klingon diaspora pretty much subscribed to just one sort of do, as well, with just the humans with a hair out of place.