The clue may be in the name. Superman, Spider-Man, Batman, Iron Man. Be it a bird or a plane or a superhero streaking across the sky, the one certain thing is that it is not a woman.
On the eve of this week's premiere of the latest Superman film, Man of Steel, one of the genre's most successful directors attacked the Hollywood establishment for failing to make superhero films with female leads.
Joss Whedon, director of last year's $1.5bn-grossing comic-book epic The Avengers, declared himself "pissed off" by the lack of positive female role models for young superhero fans.
Whedon, who also created the TV series Buffy the Vampire Slayer, suggested studios were denying young girls a "cultural reflection of themselves" by refusing to make superhero blockbusters with female leads.
"Toymakers will tell you they won't sell enough," he claimed. "And movie people will point to the two terrible superheroine movies that were made and say, 'You see? It can't be done.' It's stupid. My daughter watched The Avengers and was like, 'My favourite characters were the Black Widow and Maria Hill,' and I thought: 'Yeah, of course they were.'"
His words are likely to carry weight. The Avengers became the third-highest grossing film of all time last year and a sequel is in the works. The film featured a whole gang of superheroes including Scarlett Johansson's Black Widow and Cobie Smulders's intelligence agent Maria Hill.
Whedon suggested that if no one made a good "superheroine film" soon, he'd do it himself.
Candidates for blockbuster treatment could include Wonder Woman – whom Whedon has tried to bring the screen before. The Man of Steel writer David S Goyer has also expressed an interest in writing a film treatment for Wonder Woman, or Diana of Themyscira as she is known to fans. Last month, the Marvel Production boss Kevin Feige announced plans to make a female superhero film, saying: "It's just a matter of finding the right storyline, the right filmmaker, the right time.''
Hopes for a successful big-screen treatment have been raised by a wave of blockbusters and critical successes featuring strong female leads, including The Hunger Games (2012), starring Jennifer Lawrence.
The superhero genre, however, remains haunted by the memory of 2004's Catwoman, which starred Halle Berry and bombed with the critics and at the box office. The second "terrible" movie that Whedon refers to is most likely Elektra (2005), with Jennifer Garner.
Whedon's next film, meanwhile, is an adaptation of Shakespeare's Much Ado About Nothing – released in the UK on the same day as Man of Steel. The play features one of the Bard's strongest female characters, Beatrice, who memorably declares she will not marry "till God make men of some other metal than earth". Perchance she'll give the Man of Steel a run for his money at the box office.