"A study completed recently in December 2013 on nearly 1,000 brain scans has surprisingly confirmed what many of us thought…that there are major differences between the male & female brain. Women’s and men’s brains are indeed wired in fundamentally different ways.
The research showed that on average, female brains are highly connected across the left and right hemispheres, and connections in male brains are typically stronger between the front and back regions. Men’s brains tend to perform tasks predominantly on the left-side, which is the logical/rational side of the brain. Women, on the other hand, use both sides of their brains because a woman’s brain has a larger Corpus Callosum, which means women can transfer data between the right and left hemispheres faster than men." (Gender and The Brain,
fitbrains.com)
Chess is a game involving "logic and rationality". IMO there's nothing wrong or sexist about saying that because of this, men will be stronger chess players ON AVERAGE.
That being said, I totally support getting more girls playing chess. Although the chess tournament scene is currently something like 98:2, chess in school programs and clubs are getting tons of girls learning and enjoying the game. I expect that in the coming years, we will see many more women playing chess. I'm already starting to see many young girls playing in tournaments, and at high levels too. At the US Supernationals, I just played an 11 year old girl rated over 2000 USCF.