Here's yet another way to tell that you're old.
A Pennsylvania State study published this week has found that people use Instagram in lots of different ways—and you can pretty easily predict someone's age based on what's in their feed. However, the differences aren't necessarily ones that you'd predict.
Teens reply to comments at an average response time of 7.2 minutes, whereas adults take their time and don't reply for around 30 minutes. Maybe because of having more going on in their lives than Instagram and Snapchat?
Another way to distinguish youngs from olds is that teens have fewer posts than adults but the posts have a lot more likes and comments. Is this because there are just more teens on Instagram—nope. It's because teens are more likely to delete posts that aren't doing well because internet likes = IRL friendship-o-meter.
"Teens want to be very popular so they're very conscious of the likes they're getting," Dongwon Lee, an associate professor in the school's College of Information Sciences and Technology who co-authored this research, told the Atlantic.
The Washington Post points out a May study also found differences in the types of things adults and teens posted. Adults, ages 30-39 for purposes of this study, posted more about their location and nature, and had much more variety in their locations, which makes sense because adults love to brag about where they travel.
This article originally appeared on Cosmopolitan.com. Minor edits have been made by the Cosmo.ph editors.