Most of the world's population is multilingual [1], hence it doesn't correlate with much anything on a wider scale. The list of multilingual areas is very long

Most of the world's population is multilingual [1], hence it doesn't correlate with much anything on a wider scale. The list of multilingual areas is very long and nuanced [2] and the implications and correlations in each location are as widely varied as the list itself. As other commenters have already pointed out, the study took place in Barcelona, where multilingualism is prominent and doesn't correlate with any specific group or trait. [1] https://en.wikipedia.org/wiki/Multilingualism#Myths https://en.wikipedia.org/wiki/Multilingualism#Myths [2] https://en.wikipedia.org/wiki/List_of_multilingual_countries_and_regions https://en.wikipedia.org/wiki/List_of_multilingual_countries...