Seeing a Big Rule-Breaker Made People Break More Rules in a 750-Person Test. A Third Held the Line.

On the screen, a shooting star streaks across a row of 100 squares, and one square glows brightest. The task is to click it. Here is the catch: squares to the right of the brightest one pay more, and the further right you click, the bigger the payout. Every click is a tiny decision about whether to follow the rule or take the money.

That was the setup for 750 people in the United States in an online experiment published October 21 in Proceedings of the Royal Society B. Dr Lucas Molleman of the University of Amsterdam is the first author. The Guardian reported that participants were split roughly evenly between Republicans and Democrats. After each choice, they saw what another participant had clicked, how far that click strayed from the glowing square, and the other person's political affiliation. Then they could change their own answer. The round repeated six times.

Worth noting: rule-breaking was common from the first click. In the initial choices, before any influence, 23 percent went to the highest-paying square.

What moved people's clicks

The pattern was lopsided. Seeing others follow the rule slightly lowered a person's own rule-breaking. Seeing a small violation, a click a third of the way to the right of the glowing square, slightly raised it. Seeing a flagrant violation, further right still, sharply raised it. The authors' abstract says observing full compliance "has little effect on curbing violations", while major violations "substantially" increase them.

Who did the rule-breaking mattered too. The effect was stronger when the person on screen shared a participant's political leaning, which Molleman told the Guardian fits earlier research on aligned groups. The abstract frames it as a closeness effect: major violations spread most when committed by someone who is socially close.

From a screen of squares to a crowd

The team then fed the observed behavior into computer simulations of larger groups. In the abstract's framing, a pattern where small violations invite bigger ones can set off a "slippery slope" to the point where nobody follows the rule. Molleman put the stakes in plain terms: a minority of escalators could cause a collective to "spin out of control."

The sample is decent for a behavioral experiment, and the six-round design shows people changing their minds in real time. But the simulation is an extrapolation. It treats the shares of followers, copiers and escalators measured on a squares task as if they would hold in a firm, a classroom or a town.

What the squares can't tell you

Prof Stephen Reicher of the University of St Andrews, who was not involved, flagged two limits to the Guardian. The task is abstract, and nothing bad happened to anyone who broke the rule, so its relevance to real-world misconduct is unproven. He also said the results cut against a simple contagion story, because whether we are influenced depends on who the others are. People do not riot just because they see rioting, he said, and many who watch it help clean up afterward.

There is a gap in this account, too. The paper itself sat behind a publisher block when this was written, so it rests on the authors' abstract and the Guardian's reporting. The Guardian did not say how large the payouts were.

The idiom says one bad apple spoils the barrel. In this experiment it took a visibly worse apple than the ones already in view, ideally one that looked like a neighbor. And a third of the barrel stayed sound regardless.