When it comes to tests and exams, girls generally do better than boys.
Girls beat boys in the new grammar, punctuation and spelling test in this year's Key Stage 2 Sats in England¹.
In GCSEs in England, Wales and Northern Ireland, girls got more A* and A grades².
But this isn't a recent thing - in fact it's been this way for years. No one's sure why this happens but researchers hope to find out.
Bonny Hartley from Plymouth University said: "Children believe girls behave and perform better than boys, and they also think that adults think this too."
"Boys perform less well when they're aware of these expectations," she said.
Some people think there's a lack of male teachers or that classes are just not interactive enough for boys.
Why do girls do better than boys?
- Are we influenced by TV shows that show boys as being naughty?
- Or is there a lack of male role models in schools?
I think girls do better in school because lots more boys mess about in class.
Kate, Derbyshire, England
I think it's because there are not enough male teachers in schools. In my old school there was only one male teacher.
Dom, Bucks, England
I think it is all about the student and how they take their work. I think it is wrong for people to say that girls are smarter than boys.
Sameer, London, England
I think it all depends on the pupil and how much they are willing to work. Everyone will get distracted occasionally so it is not just boys.
Kiera, London, England
I think that boys generally mess around during class and miss out important information although girls can do this too. Maybe that's why they don't do as well as the girls.
Hannah, Somerset, England
Boys are probably influenced by TV shows and there aren't enough male role models in the school in general. In my school we have lots of male teachers but all the boys continue to misbehave.
I think girls do better than boys because boys are the ones who normally misbehave in class. Also maybe boys don't handle pressure as well as girls do.
Claire, London, England
I think boys are not always liked by teachers and girls are always the teacher's pet and that makes me feel a little less appreciated.
Cameron, Glasgow, Scotland
I think girls and boys are the same at school, some just do better than others.
Grace, Staffordshire, England
I think that girls are generally more motivated towards school but if boys put there minds to it they can catch up with us girls on the academic ladder.
Ruby, Worthing, England
I think boys are as smart as girls, but girls tend to chat more in class. Boys have more stress on them because boys are not expected to be clever. However, some boys are very intelligent like some girls.
Joshua, Newark, England
I think girls want to be good at school but when boys try they get picked on for being bright.
Abbie, Stoke-on-Trent, England
I think girls do better in school as most of the time all the boys in my class just muck around by talking.
Daniel, Andover, England
In my school there's only one male teacher. Maybe that's why...
Elissa, Shrewsbury, England
I think that there are too many TV shows and magazines which show boys being naughty.
Isabel, London, England
Girls do better at school, but saying that there is no proof that girls are smarter. It's probably because there's a lack of male teachers.
Izaak, Cheadle, England
I think it's because boys don't pay attention and us girl just work. But then some boys only do it because they are pressured.
Annie, Stoke-on-Trent, England
I think that boys aren't as good in school because they don't listen.
Elizabeth, Manaccan, England
I think girls are better than boys because if boys are smarter they are classed as geeks or nerds.
Hannah, Coventry, England