A recent grocery run in Brooklyn left me properly confused. When I approached the registers, little coconut waters in hand, two options presented themselves: I could get in the self-checkout line, in which dozens of headphone-wearing customers thumbed through their phones. Or I could go through the staffed checkout lane, which had no wait at all. What a bunch of schmucks! I thought. I breezed through the cashier’s lane and was soon out the door, while many of my fellow shoppers remained in self-checkout, languishing.

One thing I thought I knew about Americans was that unless we’re waiting for something that really hypes us up—a hotly anticipated concert, the chance to buy TikTok’s artifact du jour—we don’t exactly love queuing. Whole business ventures have emerged to limit people’s time spent waiting. Meanwhile, standing in line at a grocery store or the DMV is often characterized as a universally reviled bummer. In a 1984 Time essay, one writer lamented that “waiting is a form of imprisonment,” an “interval of nonbeing.”

Apparently, though, many grocery stores across the country regularly see longer lines for self-checkout than for cashiers. A friend of mine recently told me that the line for self-checkout at her Manhattan Whole Foods tends to snake around the store; sometimes, employees encourage people to move to the shorter, regular line—yet still only a handful will defect. Posters on Reddit have witnessed this behavior in Albany, Memphis, and Ajax, Canada. Steve Caine, a Chicago-based consultant at Bain & Company who focuses partly on the grocery sector, told me he’s noticed it at his Costco too. Over the past few years, according to data from the research group NPS Prism by Bain & Company, self-checkout in general has steadily gained popularity across age groups and in both urban and suburban areas.

This willingness to wait longer for self-checkout hints at how people make plenty of imperfect decisions every day—often without much deliberation. But it could also point to a change in the way that Americans interact with one another: Many of us, it turns out, would rather not interact at all.

Lots of people might, of course, have specific reasons for choosing a long self-checkout line—it could look longer than the regular one but be moving faster, for instance. Some customers have also been known to pilfer groceries away from a cashier’s gaze; one 2023 survey found that 15 percent of self-checkout users admitted to having stolen an item. But the psychologists and grocery experts I spoke with suspected that more subtle human behavior might be at play when people choose longer lines: “We’re not rational beings all the time,” Caine told me. Most shoppers don’t approach the registers and ponder the trade-offs of each queue; the choice is likely made on autopilot, psychology researchers told me.

This kind of unconscious decision making plays a significant role in all sorts of day-to-day behavior. Joel Pearson, a neuroscientist and psychologist at the University of New South Wales, in Australia, co-authored a study in which participants chose between two images—red or green stripes—while in an fMRI machine. The researchers found that people’s brain activity revealed their choices 11 seconds before they intentionally picked an image. And a study this year found that about 65 percent of people’s behavior is chosen through habit, without conscious deliberation. In other words, many of our decisions are already made, on some level, in the lower dregs of the soup of consciousness.

People are also unlikely to revisit the decisions they make on autopilot, even when they have new information. During errands such as grocery shopping, people may take on what psychologists call an “implementation intention”: They have come with a plan (If I go to the store, then I’ll grab some Takis and go to self-checkout), are now in execution mode, and don’t easily revise their course. “They get there, there are a few extra people, they’re thinking about one thing or another,” Eldar Shafir, a behavioral-science professor at Princeton University, told me in an email, so “rather than focusing on optimizing time spent, they just stick to it.” Even if shoppers do notice a shorter regular checkout line, they may also have a hard time switching lanes because of the sunk-cost fallacy, in which people tend to follow through with decisions that aren’t panning out just because they’ve invested time or money into them.

The popularity of self-checkout, then, could suggest a subliminal shift in some shoppers’ priorities—an aversion to waiting might be outweighed these days by a reluctance to engage with other people. Regular checkout, after all, risks the frictions and foibles of human interaction. People online express concern that cashiers could be silently judging their jumbo-toilet-paper purchases, or that they could drop and bruise their fruits while scanning them. Self-checkout gives people a “perception of control,” Caine said—the promise that “I am going to be able to control my own destiny.” Shoppers might, for instance, want to Tetris their items into bags their own way, or think that they can do it faster than any employee.

For some people, though, the choice to avoid cashiers is more basic: They dread small talk. I spoke with one customer outside a Brooklyn Whole Foods who’d just chosen a seemingly longer self-checkout line because she wanted to be able to zone out and not talk to anyone—especially after a long workday. On social media, people echo this sentiment, citing social anxiety and introversion as explanations for why they opt for self-checkout. Americans are clearly living in what my colleague Derek Thompson has called the “anti-social century,” in which people regularly carve out private experiences in public. In addition to grocery shoppers, think of the gym-goers and bus riders who retreat into personal sound cocoons with the help of headphones. A big reason people used to hate lines, after all, was the boredom, which can now be largely mitigated by the carousel of glittering distractions on their phone.

As annoying as lines can be, they have always pointed to a far more primordial force: our relentless human wanting. They’re emblems of our desire, arrows made up of bodies that point right at what we crave. Self-checkout’s popularity suggests that what many people may now want at the grocery store—whether consciously or not, and no matter if it means waiting longer—is to be left alone.