The shopping cart theory is an internet meme which judges a person's ethics by whether they return a shopping cart to its designated cart corral or deposit area. The concept became viral online after a 2020 Internet meme which posits that shopping carts present a litmus test for a person's capability of self-governing, as well as a way to judge one's moral character. Detractors of the theory have cited various reasons why returning a cart is unfavorable, with concerns about leaving children unattended as one of the more commonly referenced.