Published : 22 Oct 2026, 11:29 PM
Updated : 22 Oct 2026, 11:29 PM
The notion that one bad apple can spoil the barrel has received scientific backing, with new research finding that witnessing flagrant rule-breaking can push people well beyond the violations they observe -- and potentially send an entire group into a spiral.
Researchers recruited 750 US participants, roughly evenly split between Republicans and Democrats, for an online experiment in which they were incentivised to bend the rules of a task for greater financial reward, The Guardian reports.
Participants were then shown whether others had followed or broken the rules, the degree of any violation, and the political affiliation of those others.
The results showed that while seeing minor infractions slightly increased rule-breaking, witnessing blatant violations led participants to greatly escalate their own -- sometimes exceeding what they had observed.
The effect was strongest among those who shared political leanings.
“A minority of escalating individuals, exceeding the rule violations they observe, may cause a whole collective to spin out of control,” said Lucas Molleman of the University of Amsterdam, the study’s lead author.
Computer simulations based on the experimental data confirmed the dynamic could rapidly get out of hand in larger groups, according to The Guardian.
Writing in the journal Proceedings of the Royal Society B, the researchers noted that roughly a third of participants consistently followed the rules regardless of what others did.
Prof Stephen Reicher of the University of St Andrews, who was not involved in the study, cautioned that the experiment was abstract and carried no penalty for rule-breaking, leaving its real-world relevance unproven.
He also stressed the findings pointed away from simple contagion -- whether people are influenced by others depends heavily on who those others are.