Is Boys Better At Math and Girls Better At Reading?

I just read an very interesting article on SMH Reading superiority in girls starts early, Naplan study finds. Let me first quote a few lines from the article.

The study also found that better performance in literacy was limited to girls from low and middle socioeconomic backgrounds, and only boys from high socioeconomic families did better in numeracy.

“Once you have a grasp of language and literacy you can use that in everything, so the gap could have a detrimental effect across all areas of learning [for boys].”

In maths, teachers giving more positive feedback to boys could lead to the numeracy gap that emerges in year 3, Professor Walker said.

“The way boys and girls are perceived and the feedback they get becomes a self-fulfilling prophecy,” she said.

The most interesting part to me was the fact the math advantage was only limited to boys from the higher socioeconomic background. So if as the article suggested that feedback children received becomes a self-fulfilling prophecy should have meant that regardless of their socioeconomic background would have similar gap manifest. With same logic it is unlike gender-based teaching would cause this as well. So what had caused this difference? I think this certainly deserve a more in detailed look into why it is so the case.