One in five players of EverQuest II, the online role-playing game above, is female. Credit: Sony Online Entertainment.

The words "You play like a girl" could turn out to be the ultimate compliment.

When it comes to online role playing games, women spent more time playing than men, according to a University of Southern California study of gender differences among gamers. Among those who played EverQuest II, a game developed by Sony Online Entertainment, women spent 29 hours a week in the game, compared with 25 hours for men.

"The women play more intensely than the guys," said USC economist Dmitri Williams, who co-authored the study with Mia Consalvo of Ohio University, Nick Yee of the Palo Alto Research Center and Scott Caplan of the University of Delaware. "They're less likely to quit, and they're happier playing."

The discovery is one of several stereotypes refuted by the study. Contrary to the image of the overweight nerd glued to his computer, gamers in the study were no less fit than the general population. In fact, women who played EverQuest II tended to exercise more and weigh less than the average American.

Another shattered stereotype: The pimply teenage gamer. The average age of the 7,000 players in the USC survey was 31, and gamers in their 30s outnumbered those in their 20s.

But the study also affirmed many gender tropes. For example, women ...