Because of low critical standing or low readership or some combination of both, good data about comics readership over the years is rare. We do know that comics were much, much more popular during the 1940s, when superheroes first burst on the scene, than they are today. Comics then were more like film or television—a mass entertainment option, rather than a niche one. A Market Research Company of America report from 1944 found that 95 percent of all boys and 91 percent of all girls between six and 11 read comics; 87 percent of boys and 81 percent of girls between 12 and 17, and 41 percent of men and 28 percent of women between 18 and 30. Comics scholar Trina Robbins told me that The Newsdealer, a magazine for newsstand owners, actually published figures suggesting that girls at the time read more comics than boys.

Comics in the 1940s included not just superhero stories, but romance, horror, crime, humor, and other genres, so it's difficult to know if women were reading superhero stories in particular in any great numbers. Gerard Jones in his book Men of Tomorrow mentioned a survey that showed that 90 percent of the readers of Wonder Woman were men—and if women weren't reading Wonder Woman, you'd think they wouldn't be reading many superhero titles. However, when I asked Jones for details about the survey, he said he had only heard about it second-hand, and expressed some doubt about the accuracy of the figures. Trina Robbins was even more skeptical, declaring that the survey results were "absolute bullshit!" She herself had read Wonder Woman, Gloria Steinem had read Wonder Woman, and both of them remembered other girls reading the series as well. Comics scholar Jeet Heer pointed out to me that there were substantial numbers of female superheroes in the 1940s, which suggests that publishers believed that there was a female audience out there.

Large numbers of women, then, may well have read superhero comics in the past. More recently, though, the gender of readers seems to have skewed very much male. Neil Shyminsky, an instructor at the University of Toronto, moderated the X-Universe Message Board at comicboards.com in 2004 and 2005, when it was the most heavily trafficked X-Men message board on the Internet. When he posted a voluntary survey to find demographic data, and the response was 95 percent male.

Obviously, Shyminsky's results might not be representative of the superhero comics readership as a whole—but other surveys tend to confirm his figures. In 2008, Heidi MacDonald at the comics news site The Beat pointed to a demographic survey suggesting that superhero comics readers were 90 to 95 percent male. She added, "every comics reader demographic survey we've EVER seen has 5-10% female readership." Similarly, Matthew Klokel, a retailer in Washington, D.C. at Fantom Comics Shop, estimated his store’s superhero comic readership at about the same percentage circa 2008: 90 to 95 percent male.