Philosopher Peter Carruthers (Maryland) kindly calls my attention to this new work (co-authored by philosopher Sarah-Jane Leslie [Princeton]):
You and your readers might be interested in this new paper from Sarah-Jane Leslie and Andrei Cimpian, following up on their earlier work with adults:
Bian, L., Leslie, S. J., & Cimpian, A. (2017). Gender stereotypes about intellectual ability emerge early and influence children's interests. Science, 355(6323), 389–391.
(As you may recall, the earlier finding was that gender distribution across disciplines is predicted by the extent to which people believe that you need to be brilliant to do well in that discipline.)
A pdf of the paper is accessible from Cimpian's page below, which also contains links to reports in the NY Times, the Post, the Guardian, and elsewhere.