Why don't people return their shopping carts?

Summary

I arrived on the scene early one Saturday. The suspects were long gone, but the evidence remained. One cart was wedged into a curb, another sat toppled over in a parking spot, a third drifted like a metal tumbleweed across the lot. My question: Why don’t people return their shopping carts? I’m a psychologist who has spent the past decade studying how we think about our own behavior in relation to others. Perhaps the choice to not return a shopping cart seems trivial, but what we do with our cart says a lot about how we think about others and what we believe we owe one another (or don’t). I’ve never understood why people don’t put their carts away. In high school, I worked as a shopping cart attendant at my local grocery store, shepherding carts across the lot. Since then, for reasons I can’t fully explain, people’s failure to return their carts bothers me more than it probably should, with every trip to the grocery store a reminder of the special kind of havoc humanity is capable of. Then last year, on a windy weekend morning in a Wegman’s parking lot, it hit me. Not a cart, but the realization that I can do something productive about it. So I approached the question of shopping cart abandonment the way I would any puzzle about human behavior: I collected data. My evidence came from an unlikely source: Cart Narcs, a small group whose mission is to encourage cart return, sometimes gently, sometimes less so. They upload their efforts on their YouTube channel, which boasts hundreds of videos recorded between 2020 and 2025, taking place mostly in California, but also Nevada, Texas, Louisiana, New York, Canada, Australia, and England. Cart abandonment, it turns out, knows no regional bounds. As of September 2025, these videos have collectively been viewed over 90 million times. (See below for one of the tamer videos.) I watched a total of 564 encounters between Cart Narcs and cart abandoners. These don’t represent a perfectly random sample of interactions, but together t...