... no it isn’t. It’s saying the differences that do exist are related to sex, not gender - any statistical relationship to gender is mediated through the relat

... no it isn’t. It’s saying the differences that do exist are related to sex, not gender - any statistical relationship to gender is mediated through the relationship to sex because gender is often correlated to sex ... but there are many people for whom this is not the case. So gender can’t be responsible for physical differences. Only sex, which is physical, could be correlated with physical/neurological differences.