A European study on this very problem seems to prove, or at least advocate, that the results are highly dependent on the type of reading and writing suggested in the test.
Try sports articles, or applied technology and applied science articles, car mechanics and extreme experiences. And there are many other subjects that are excluded from the tests. Boys will dominate on such subjects.
Women seem to be more reactive to standard scholastic reading and writing, more than boys anyway.
Frankly why should boys and girls be tested on the same test as for their ability to read and write. One is good at reading and writing when one is reading and writing on and about what they like, they prefer.
Such tests should be: 1- determine what the subject likes. 2- make him or her read and write on this subject. The results will — in fact shall — be quite different from what they say generally.