From the Wikipedia article, it seems like doula is of fairly recent American coinage. And the fact that it's comes up as a routine topic probably says more about your social circle than anything else.
> And the fact that it's comes up as a routine topic probably says more about your social circle than anything else.
Not really. Unless my 'social circle' also has a monopoly on metrics like Google Trends, doula is a more popular term than either aileron or azimuth in the majority of countries for which metrics are available.
