Sound inventories and population size

When I had lunch with two phoneticians the other day, the question came up whether there is a correlation between the size of the phoneme inventory of a language and its population size. Neither of us knew, and we started to speculate in which direction it should go. My guess was that larger languages should have smaller inventories and vice versa, while the two expert expected the opposite. One of the reasons for my conjecture was the observation by Lupyan and Dale (2010) in Plos ONE (Lupyan G, Dale R (2010) Language Structure Is Partly Determined by Social Structure. PLoS ONE 5(1): e8559. doi:10.1371/journal.pone.0008559) that larger languages tend to have less morphological complexity (and vice versa). Continue reading