Female gamers are used to putting up with sexist claptrap - both from the companies that design games and other players. So a study by psychologists at Nottingham Trent University showing that 70% of them chose to construct male characters when given the option by online games, should come as no surprise.

Anyone who has played video games with any regularity will know that character design is one of those areas where gender stereotypes run riot. Most pre-packaged characters are white, male and buff. Female characters are few and far between, and when they do appear they are usually highly sexualised or passive, or both. Game architects just don't seem to be able to look beyond those pneumatic breasts.

But the study focused on role-playing games where you get to choose everything about your avatar, including age, shape, ethnicity and gender. Given limitless possibilities, why would women choose to change their sex in far greater numbers than men opting to play women?

As the psychologists suggest, one reason could be the sexism and sexual harassment to which women are subjected online. A cursory glance at the comments under almost any YouTube video featuring a woman demonstrates that just being female is enough to draw a vicious response from a stream of misogynist and anonymous commenters. Technology blogger Kathy Sierra abandoned her website after the harassment directed towards her escalated to unbearable levels. When Second Life millionaire Ailin Graef appeared on a chat show in the virtual world to discuss her success on the platform - which is more 3D chatroom than game - her character was swarmed by flying pink penises (the attack was arranged by "griefers" - users who spend all their time harassing others).

Then you have the "tits or GTFO" internet trend, whereby new posters on message boards who identify themselves as female are requested to post photos of their breasts or "get the fuck off". When it comes to multiplayer games, such as World of Warcraft, women must also face down a whole set of assumptions about their ability to play. Or they could just sidestep all this and construct male characters and avatars.

But let's not forget that, just like TV or film, gaming is a form of escapism. What does it signify if I chose to play a male elf instead of a female elf? We live in a society that rigidly polices our gender expression - in some ways, what is interesting is not that so many gamers chose to play characters of another gender, but the surprised reaction such virtual experimentation produces.