This App Measures Which Friends Are Stressing You Out And Blocks Them For You

Maybe you just don’t have the willpower to do what’s right for yourself.

It’s usually pretty clear when you think someone’s a jerk. But a new app called “pplkpr” is designed to catch more subtle patterns over time. By measuring your emotions via a heart-rate monitor, the app figures out which friends stress you out more often than they make you happy. Then it manages your social life so you don’t hang out with them anymore.


Created by two artists, the app is partly tongue-in-cheek, designed to raise questions about whether we actually need to digitally track every aspect of our lives.

“We were looking at this increasing trend toward wearables and quantified life and we wondered: When does it go too far?” say artists Lauren McCarthy and Kyle McDonald. “This app is a critique of trends we see in big data, surveillance, and algorithmic living. We hope to provoke conversation around these issues and get people to think critically about the future toward which we may be heading.”

At the same time, they realized that the app could actually be useful. Toxic friends, after all, can literally make people sick. And it can be hard to recognize less-than-healthy relationships when you’re in the middle of them.

The artists were inspired by experimental clothing developed at MIT to record domestic violence. “While the data could provide evidence for the victim to use against their attacker, the other intent was actually to provide data to the victim to help them see the violence themselves,” say McCarthy and McDonald. “What would the equivalent look like for abuse that isn’t physical?”

The app also tracks positive emotions, and automatically invites the friends you like to hang out more often. It pairs with a smart watch that monitors heart-rate variability–a known measure of stress–and uses a custom algorithm to crunch that data and determine your mood. If you’re noticeably emotional, the app pings you afterward to ask what was going on and who you were with. Over time, it charts which friends are making you happiest or most crazy.

In a week-long user test, college freshmen who tried the app seemed to find it useful. (“Maybe I shouldn’t hang out with Mark,” one student says in this video. “Maybe he’s kind of a dick”).


“The students at CMU were really open-minded about the app,” say the artists. “They didn’t seem to have as many preconceived biases against the potential for this kind of technology to have a positive impact on their life. They went into it with few expectations or assumptions, and I think that enabled them to have a real experience, not just a hypothetical one, which is our intent with realizing this to the extent of a working app.”

The artists themselves had a different experience. “We were surprised at what an intense effect it had,” they say. “You think that you know how you’re feeling and you’re being honest about it, but when there’s a sensor tracking your emotions and acting on that data, you suddenly feel a lot more exposed. It’s somewhere in between a heightened sense of awareness and surveilled paranoia.”

The point of the app, they say, is to make people think a little more critically about the other apps in their lives. “We wanted to create a piece that addressed more of the nuance and contradictions of these new technologies,” they explain. “It was important to build a functioning app–this goes beyond speculative design fiction. Because it is a real app, when you encounter it, you are faced with choices and questions. Will you download it? Will you use it? What happens if it actually improves your life?”

“We do think there is a huge potential here for this app or others like it to change behavior,” add the artists. “That’s why it is so urgent for us to question how we’re being changed, and whether we actually want that.”


About the author

Adele Peters is a staff writer at Fast Company who focuses on solutions to some of the world's largest problems, from climate change to homelessness. Previously, she worked with GOOD, BioLite, and the Sustainable Products and Solutions program at UC Berkeley.