I notice it most when I am choosing where to eat. Two cafés sit on the same street. One has a queue out the door; the other has empty tables and the same coffee. I will join the queue. I have done it enough times to know that the queue is not telling me the coffee is better. It is telling me that other people are there, and somewhere in the back of my head that registers as a reason.
The book everyone is already reading. The restaurant that is hard to get into. The opinion that, when I check, seems to be the one most of my feed already holds. In each case the same small mechanism is running underneath: I am treating the size of the crowd as if it were evidence.
This has a name; the bandwagon effect. It describes the tendency to adopt a belief, habit, or opinion largely because we can see other people doing the same. The economist Harvey Leibenstein gave it theoretical footing in 1950, describing the pull to fall in line with the majority. The term itself is older, borrowed from 1800s American political campaigns, where climbing aboard a candidate’s literal bandwagon meant aligning yourself with apparent momentum.
What makes it interesting, rather than just a tidy label, is the direction of travel. The believability of an idea tends to grow with the number of people who already hold it. Popularity is not just a result of an idea being persuasive. It can be the thing doing the persuading.
The mechanism is a form of social proof. When we are uncertain, and we are uncertain more often than we admit, we look to other people for a read on what is correct. The number who hold a view becomes a shortcut for the quality of the view.
I’m not a psychologist, and the studies here are findings from particular groups of people, not settled science or universal rules.
A 2022 study from a team at UC Berkeley tested this directly. Across two experiments, Evan Orticio, Louis Martí and Celeste Kidd found “increasing people’s perceptions of the general prevalence of a belief can cause them to endorse that belief more strongly, devoid of any direct evidence.” It’s one study and should be taken as a clue, not a law but the detail that stays with me is that no actual evidence had to change hands. Only the sense of how many other people were on board.
I recognise the shape of it in my own life. When I left a finance job and ended up in Vietnam, then drifted into freelance writing, it felt entirely like my own decision. Looking back, I had been reading a whole canon of leave-the-corporate-job books, the Tim Ferriss school of it, and so had a visible group of people around me online. I was not weighing independent evidence about whether the move was right for me. I was, in part, joining a crowd that already looked like it had figured something out. It felt like stepping off the script. It was closer to stepping off one script and onto another.
Here is the uncomfortable part. The signal we lean on, how many people hold a belief, is independent of whether the belief is correct. A true idea and a false idea can both look popular, and from the outside they generate the same cue.
The sociologists Matthew Salganik and Duncan Watts built a striking demonstration of this. In an online music market with 12,207 participants, they took unknown songs and secretly inverted the real popularity rankings, showing people fake numbers. They report that “most songs experienced self-fulfilling prophecies, in which perceived—but initially false—popularity became real over time.” A false signal, once seen, could manufacture the very thing it claimed to measure. The authors are careful, calling the results “partial and speculative,” and they note the best songs eventually clawed their way back. So again this is not an iron rule that lies always win. But it shows that perceived popularity can pull real adoption along behind it, quality more or less to one side.
Set the two findings next to each other and the worry sharpens. The Berkeley work suggests perceived prevalence nudges what we believe. The Music Lab work suggests perceived popularity can become real. The thing we trust as a proxy for truth is, at least some of the time, a proxy for nothing more than itself.
It seems the pull toward the crowd is something we have been trained over a very long time to feel, and I feel it as much as anyone reaching for the busier café.
I don’t have a fix but what I have landed on is a single question, and it grew out of something I have come to believe about going against the grain. The anti-default path, the deliberately contrarian one, is itself a script. Picking the empty café on principle is still letting the crowd decide, just by reacting against it. So the question is not “what does everyone think” and it is not “what does nobody think.” It is closer to this: can I give a real reason for holding this belief that is actually mine, not borrowed from a book, not inherited, not the residue of how many people around me happen to agree? And then the harder follow-up, asked a second time, when the first answer was a little too quick: does that reason still hold up?
Most of the time, if I am honest, the reason I can offer is some version of “lots of people seem to think so.” Which the Berkeley researchers would probably point out is exactly the input that moves us “devoid of any direct evidence.” That is not nothing. Other people are often right, and outsourcing some judgment to the crowd is mostly how we get through a day without re-deriving everything from scratch. The trouble is only that the crowd can look the same whether it is right or wrong.
If any of this is sitting heavier than it is interesting, talking it through with someone you trust, or a therapist, is worth more than another article.
