Father’s Day is coming up this weekend: a time when dads all over the country open cards, get taken out to lunch, and tell stories about parenting their kids. It’s also a time for kids to reflect on their relationships with their fathers, an experience that might be very different depending on gender. A new study finds that dads can be quite different with daughters than with sons, a pattern researchers are working to fully understand.

For the study, published in May in the journal Behavioral Neuroscience, researchers at Emory University and the University of Arizona used recording equipment to monitor 52 new dads for 48 hours while they interacted with their children, who were between one and two years old. Watching the behavior of the new fathers, researchers noticed that the way dads treated their girl babies was significantly different than the way they interacted with boys.

When interacting with daughters, dads in the study tended to sing and whistle, as well as use emotive and analytical language. They also used more words pertaining to the body such as “cheeks,” “fat,” and “belly.” When spending time with their sons, dads were much more aggressive, engaging in (baby-appropriate) roughhousing and using competitive language, such as “proud” and “win.”

Jennifer Mascaro, an Emory University researcher who worked on the study, told the Washington Post that until now, there has been very little research on how fathers interact with their children. This is in large part due to the fact that, until very recently, dads just weren’t all that involved with their kids. The Post cites a 2014 study that found that working dads spend an average of 35 minutes with their children per day; this doesn’t sound like a lot, but fathers were only spending about five minutes each day with their kids in 1974. (To compare, moms now spend a full hour with their kids each day.)

The new study also involved an experiment where fathers were shown photos of their baby with different expressions: sad, neutral, and happy. When the dads were shown photos of their daughters, they showed a greater neural response overall; in particular, they exhibited a strong response in their brain’s reward system when shown happy photos of their girls. With sons, however, the response was different. When dads looked at pictures of their sons, they had the strongest response to neutral expressions.

Mascaro told the Post that researchers aren’t totally clear as to why dads responded this way to photos of their sons, but says it might have something to do with how dads interact with their sons in person. “Rough and tumble is this special situation where this kind of movement is okay, but you really have to attend to your partner’s emotions: Are they still having fun? I think it’s really intriguing to think that attending to more ambiguous facial expressions might be important,” she tells the Post.

This research reveals that the idea of dads being tough on their sons but a bit softer with their daughters has some truth behind it, and is an important step in understanding how fathers impact their children, and the role they play in raising their kids. Susan Gelman, a University of Michigan professor of psychology who was not associated with the study, tells the Guardian that we can learn a lot about gender roles from these findings.

Gelman says the study has “potentially important implications regarding the implicit messages that boys versus girls receive from an early age. Gender stereotypes and biases place limits on boys as well as girls, so it’s important for parents to be aware of how they may be passing along their own gender biases.”

Though there are many interesting and helpful insights to pursue based on this research, Moscaro tells us via email that because the study only took place over the course of 48 hours, it would be “premature to make recommended parenting changes based on these findings alone.” But in light of other research on fathers, there are still some helpful conclusions to be drawn.

For example, “Previous research indicates that rough and tumble play facilitates emotional and social development, so it is potentially important that fathers are engaging in more of this behavior with sons,” Moscaro tells us.

Overall, according to Moscaro, “If fathers are engaging in less of these positive behaviors with one sex vs. the other based on subtle gender biases about how we think we should interact with boys and girls, then I think we can say that it’s important to be aware of, and try to address, some of the social biases that affect all of us.”

While more research is necessary, Moscaro and her colleagues’ findings begin to shed light on how dads are interacting with their children, and the impact they have on their kids’ lives.

What are your thoughts on the differences between the way dads treat their daughters compared to their sons? Tell us on Twitter @BritandCo.

(Photos via Getty)