Data from: Jeans and language: social networks and reproductive success are associated with the adoption of outgroup norms

Traditional norms of human societies in rural China may have changed due
to population expansion, rapid development of the tourism economy and
globalization since the 1990s; people from different ethnic groups might
adopt cultural traits from outside their group or lose their own culture
at different rates. Human behavioural ecology can help to explain adoption
of outgroup cultural values. We compared the adoption of four cultural
values, specifically speaking outgroup languages/mother tongue and wearing
jeans, in two co-residing ethnic groups, the Mosuo and Han. Both groups
are learning outgroup traits, including each other’s languages through
contact in economic activities, education and social networks, but only
the Mosuo are starting to lose their own language. Males are more likely
to adopt outgroup values than females in both groups. Females of the two
groups are no different in speaking Mandarin and wearing jeans, whereas
males do differ, with Mosuo males being keener to adopt them than Han
males. The reason might be that Mosuo men experience more reproductive
competition over mates than others, as Mosuo men have larger reproductive
skews than others. Moreover, Mosuo men but not others gain fitness
benefits from the adoption of Mandarin (they start reproducing earlier
than non-speakers). This article is part of the theme issue 'Social
norm change: from evolution to policy intervention'.