Modern movie superheroes are bad role models for boys as they promote violence and revenge as a way of life, claim psychologists.
Watching superheroes beat up villains may not be the best image for boys to see if society wants to promote kinder, less stereotypical male behaviours, they claim.
Unlike the comic heroes of the past who often held ordinary day jobs and believed in social justice, the new breed of Hollywood superheroes are aggressive, sarcastic and rarely speak about the virtue of doing good for humanity.
Dr Sharon Lamb, of the University of Massachusetts, said that modern depictions of superheroes like Iron Man are often playboy millionaires who are only ruled by selfish goals.
"There is a big difference in the movie superhero of today and the comic book superhero of yesterday," Dr Lamb told the annual Convention of the American Psychological Association.
"Today's superhero is too much like an action hero who participates in non-stop violence; he's aggressive, sarcastic and rarely speaks to the virtue of doing good for humanity.
"When not in superhero costume, these men, like Ironman, exploit women, flaunt bling and convey their manhood with high-powered guns."
The comic book heroes of the past did fight criminals, she said, "but these were heroes boys could look up to and learn from because outside of their costumes, they were real people with real problems and many vulnerabilities," she said.
To understand how the media and marketing managers package masculinity to boys, Lamb surveyed 674 boys age 4 to 18, walked through malls and talked to sales clerks and came to understand what boys were reading and watching on television and at the movies.
She and her co-authors found that marketing managers take advantage of boys' need to forge their identity in adolescence and sell them a narrow version of masculinity.
They can either be a "player" or a "slacker" – the guy who never even tries – to save face.
"In today's media, superheroes and slackers are the only two options boys have," said Dr Lamb. "Boys are told, if you can't be a superhero, you can always be a slacker.
"Slackers are funny, but slackers are not what boys should strive to be; slackers don't like school and they shirk responsibility.
"We wonder if the messages boys get about saving face through glorified slacking could be affecting their performance in school."
She said that original superheroes like Superman who was a reporter by day and the Green Lantern, who was a railroad engineer, were invented to fight for social justice and were a reaction to the rise of fascism.
But the new breed of superheroes only thought about themselves.
She said boys need to be taught from an early age to distance themselves from the se images and encouraging them into finding the lies in the messages can help.