
A college friend of mine started majoring in Computer Science but then switched to Biology. Her reason: "Computers didn't play as active a role in my life growing up as they did for boys." Plus, per her, it was just a culture she didn't get.
Granted her growing up was in the late 80's, early 90's when computers weren't as ubiquitous in households as they are in the 2000-s.
This is a good read:
"Justine Cassell, director of Northwestern University’s Center for Technology & Social Behavior, has written about the efforts in the 1990s to create computer games that would appeal to girls and, ultimately, increase the representation of women in computer science. In commenting as a co-contributor in a new book, “Beyond Barbie and Mortal Kombat: New Perspectives on Gender and Gaming,” Ms. Cassell writes of the failure of these efforts, “The girls game movement failed to dislodge the sense among both boys and girls that computers were ‘boys’ toys’ and that true girls didn’t play with computers.”
She said last week that some people in the field still believed that the answer to reversing declining enrollment was building the right game. Another school of thought is what she calls the “we won” claim because women have entered computer-related fields like Web site design that are not traditional computer science. Ms. Cassell points out that it’s not much of a victory, however. The pay is considerably less than in software engineering and the work has less influence on how computers are used, and whether this actually accounts for the diminishing numbers of female computer science majors remains unproved."