Partial Truths

A fast-food chain once attempted to compete with McDonald's quarter-pounder by introducing a third-pound hamburger, only for it to fail because consumers mistakenly thought a third pound was less than a quarter pound, reasoning that three is less than four. Similarly, a surge of suicides among teenagers who played Dungeons and Dragons prompted panic among parents and the media, leading them to believe that D&D was causing these suicides. In reality, teenage D&D players died by suicide at a much lower rate than the national average. Errors like these can be traced from antiquity to the present, from the Peloponnesian War to the COVID-19 pandemic. How and why do we keep falling into these traps?

James C. Zimring argues that many of the mistakes the human mind consistently makes boil down to misperceiving fractions. We encounter numerous statistics that are essentially fractions, such as percentages, probabilities, frequencies, and rates, and we tend to misinterpret them. Sometimes bad actors manipulate us by cherry-picking data or distorting how information is presented; other times, careless communicators inadvertently mislead us. In many cases, we deceive ourselves and have only our own minds to blame. Zimring also explores the counterintuitive reason that these flaws might benefit us, showing that individual errors can significantly aid in problem solving by groups.

Blending key scientific research in cognitive psychology with accessible real-life examples, Partial Truths helps readers identify the fallacies lurking in everyday information, from politics to the criminal justice system, from religion to science, from business strategies to New Age culture.