i found this:
New research shows that girls are ahead in every subject, including math and science. Do today's grading methods skew in their favor? As the new school year ramps up, teachers and parents need to be reminded of a well-kept secret: Across all grade levels and academic subjects, girls earn higher grades than boys.Sep
and this:
All or most of the major tests commonly used to measure intelligence have been constructed so that there are no overall score differences between males and females. Thus, there is little difference between the average IQ scores of men and women.
the first one seems more correct but idek