The way kids' personalities develop may have more to do with their peers than their parents, according to a new study.

Contagious Preschool Personalities
Credit: Fh Photo/Shutterstock

My 3-year-old is stubborn like I am; she's also very sweet and lovable like my husband. But now, new research out of Michigan State University and published online in the Journal of Personality and Social Psychology finds that kids' personality traits are not just genetic; in fact, they may be contagious among their peers!

"Our finding, that personality traits are 'contagious' among children, flies in the face of common assumptions that personality is ingrained and can't be changed," explained Jennifer Watling Neal, associate professor of psychology and co-investigator on the study, in a press release. "This is important because some personality traits can help children succeed in life, while others can hold them back."

In other words, who your child is surrounded by can have long-lasting effects on their lives. As the study's co-researcher Emily Durbin commented, "Parents spend a lot of their time trying to teach their child to be patient, to be a good listener, not to be impulsive. But this wasn't their parents or their teachers affecting them—it was their friends. It turns out that 3- and 4-year-olds are being change agents."

I think I speak on behalf of all parents when I say: Whoa.

Researchers looked at two preschool classes; one made up of 3-year-olds, and the other of kids who were 4. What they found, was that over the course of a year, kiddos whose peers showed characteristics of being extroverted or hard-working became like them. But kids whose 'lil buddies were overanxious or easily frustrated, interestingly, did not take on those traits.

The takeaway: As parents, our influence may only be part of the picture when it comes to how our children's personalities develop. Friends may also play a role. But it's not worth it to get too crazy over-analyziing who is in a kid's class, in my opinion. It may be worth it to arrange play dates with kids you think are positive influences, though. And it's definitely worth it to reinforce behaviors and traits you'd like to see your child foster, through your own words and actions.

Melissa Willets is a writer/blogger and a mom. Find her on Facebook where she chronicles her life momming under the influence. Of coffee.