Most of us tell minor lies on a daily basis—saying your partner looks great when, really, they’re having a bad hair day, or nodding in feigned agreement at your colleague’s latest political rant. Such white lies, though, don’t just help avoid scuffles or hurt feelings; they’re also an integral part of shaping how communities form, according to a new study. A group of computational scientists developed a mathematical model of how groups of people grow and change over time, and then added in a new variable: the occurrence of lies. Big antisocial lies—like lying about theft or injuring someone—led to the complete disintegration of communities, with each person in the model eventually looking out only for themselves. But smaller white lies—even at a high rate of occurrence—had a different effect on the model. People formed small, tight cliques with occasional links between groups. And these connections, it turned out, were facilitated by people who told the most white lies, the researchers report online today in the Proceedings of the Royal Society B. The mathematical model, the authors admit, is a simplified version of reality; it assumes a constant rate of lies throughout time and among all the relationships a person has. But the takeaway is clear, they say: Lies can be good for society.