Superheroes are inherently good — their epic abilities are built right into their names. As Superman, Spider-Man, Batman and the like rescue people in danger and fight crime with aplomb, we let our kids watch their movies and wear their costumes because (we hope) they're learning the importance of helping and protecting others.

But a new study finds superhero culture may not be such a good influence on kids after all. The research, published in the Journal of Abnormal Child Psychology, shows that preschoolers who frequently engage with superhero culture had "increased physical and relational aggression" after one year. The study also shows that as a result of that exposure, children were not likely to be defenders of kids being picked on, and they were not likely to be "prosocial" — meaning they weren't inclined to help others.

"So many preschoolers are into superheroes and so many parents think that the superhero culture will help their kids defend others and be nicer to their peers," said study author Sarah M. Coyne, a professor of family life at Brigham Young University, in a press release. "But our study shows the exact opposite. Kids pick up on the aggressive themes and not the defending ones."

For the study, 240 children and their parents provided a variety information about their engagement with superhero culture. Parents were asked how often their children watched such media and how much they identified with various superheroes. Kids were asked identify 10 popular superheroes, choose their favorite one and share why they liked that hero the best.

Coyne said her findings don't mean parents should eliminate superheroes from kids' media diet. After all, it's nearly impossible to avoid. At least eight superhero movie blockbusters are slated for release this year, including "Wonder Woman," "The LEGO Batman Movie" and yet another Spider-Man movie. Not to mention the toys, costumes, clothes, lunch boxes, backpacks — you name it.

"Again, I'd say to have moderation. Have your kids involved in all sorts of activities, and just have superheroes be one of many, many things that they like to do and engage with," she said.

Princesses aren't so great, either

Disney princesses It's hard to avoid Disney Princess culture, especially if you're raising young girls. (Photo: Loren Javier/flickr)

This isn't the first time Coyne has tackled the issue of how aggressive marketing influences young children. In June 2016, Coyne's research about how Disney Princess media magnifies female-gender stereotypical behavior in both boys and girls was published in the journal Child Development and made headlines around the world. The study involved nearly 200 preschoolers and their parents who, similarly to the superhero study, provided information about their level of interaction with the princess culture.

"We know that girls who strongly adhere to female gender stereotypes feel like they can't do some things," Coyne said in a press release. "They're not as confident that they can do well in math and science. They don't like getting dirty, so they're less likely to try and experiment with things."

“Disney Princesses represent some of the first examples of exposure to the thin ideal,” she added. “As women, we get it our whole lives, and it really does start at the Disney Princess level, at age 3 and 4.”

Interestingly, the boys in the study who engaged with Disney Princess media had better body esteem and were more helpful to others.

Angela Nelson ( @bostonangela ) is an exhausted mom of two young daughters and two old cats, and a Pulitzer Prize-winning digital editor with more than 15 years of experience delivering news and information to audiences worldwide.