A six-year-old boy wearing an Iron Man mask browses the toy aisle of a department store. (Seth Wenig/Associated Press)

A leading child psychologist in the U.S. says modern movie superheroes are more violent and selfish and make poor role models compared with comic book heroes of the past, the Guardian reports.

Dr. Sharon Lamb, of the University of Massachusetts, says today's superhero, as typified by Robert Downey Jr.'s character in the Iron Man movies, 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 Iron Man, exploit women, flaunt bling and convey their manhood with high-powered guns," Lamb told the annual Convention of the American Psychological Association in San Diego on Sunday.

Lamb was discussing the results from a study she conducted to find out what young boys and male teenagers were reading and watching. She said the influence of today's more self-interested, hyper-macho superheroes could harm the social skills of teenagers.

Earlier superheroes, like the original Superman and the Green Lantern (who first appeared in the late 1930s and early 1940s respectively), made better role models because they stood for social justice and offered a more nuanced version of masculinity, Lamb argued. Outside of their costumes, they "were real people with real problems and many vulnerabilities."

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