– Gender streaming among STEM fields appears already in secondary school.
– Girls are under-represented in physics, IT and advanced mathematics.
– This pattern is not driven by gender differences in prior achievement in numeracy.
– Socio-economic disadvantage has a greater adverse effect on boys than on girls.
– There is significantly less gender streaming among STEM fields in all-girls schools.
– Students with a language background other than English choose STEM fields with greater frequency than other students, reflecting their comparative advantage, while exhibiting more markedly gendered subject choices, indicating a role for cultural factors.