To reach this conclusion, author Tina Ziemek offered a pool of 34 13- and 14-year old students a selection of six Nintendo 64 titles (Yoshi's Story, Bust-A-Move, Mischief Makers, Banjo-Kazooie, Wetrix, and The Legend of Zelda: Ocarina of Time), and noted down which of the games each subject preferred to spend time with.
As it happens, the females in the group opted to play Yoshi's Story most of the time, while the males chose Zelda. Ziemek also notes that a lot of the kids commented on the easiness and accessibility of the 2D games in interviews, and that the females "disliked the confusion in the 3D video games, whether it was unclear directions, objectives, camera perspectives, or not knowing how to control the character."
Ziemek's final conclusion? That the majority of females would rather play games that are "easy," while the majority of males would rather play games that are "challenging." If Ziemek's findings are correct, this may partly explain why so many females pick up a DS -- after all, which other platform has such a delightful array of 2D software?