New Yorker has a great profile of Sheryl Sandberg with the subtitle: "Can Sheryl Sandberg upend Silicon Valley’s male-dominated culture?" Here's an excerpt about how male-dominated it really is:
Among the hottest new companies— Facebook, Twitter, Zynga, Groupon, Foursquare—none, as Kara Swisher reported in the blog All Things Digital, has a female director on its board. PayPal has no women on its five-member board; Apple has one of seven; Amazon one of eight; Google two of nine. When I asked Mark Zuckerberg why his five-member board has no women, his voice, which is normally loud, lowered to a whisper: “We have a very small board.” He went on, “I’m going to find people who are helpful, and I don’t particularly care what gender they are or what company they are. I’m not filling the board with check boxes.” (He recently added a sixth member: another man.) The venture-capital firms that support new companies have even sharper imbalances; Sequoia Partners lists eighteen partners on its Web site, none of them women.
One reason there are few female executives in Silicon Valley is that few women become engineers. In the United States, less than twenty per cent of engineering and computer-science majors are women. Girls are said to think that software and video games and computer programming are for guys. “Growing up,” Mark Zuckerberg’s older sister Randi told me, “my brother got video games and I got dolls.” For girls, there is a stigma attached to engineering, Marissa Mayer, who is now a vice-president at Google, says. “They don’t want to become the stereotype of all-night coders, hackers with pasty skin.” Michelle Hutton, who is the president of the international Computer Science Teachers Association, says, “Computer science is seen as a very masculine thing”—just “as girls don’t want to be garbage collectors because that’s seen as a boys’ thing.”