New Issue: Orbital Catastrophe Ahead? Read Now

Math against Profiling

Join Our Community of Science Lovers!


On supporting science journalism

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.


Racial profiling makes little sense, mathematically speaking. Using statistical analyses, William Press of the University of Texas at Austin has found that choosing people to screen based on ethnicity is no more effective than random checks, because nonterrorists vastly outnumber terrorists. The optimal way to screen would be to use “square-root-biased sampling,” so that someone nine times as likely to be a terrorist as the average traveler would be screened three times more frequently. This approach would turn up more terrorists in part by avoiding the repeated screening of the same innocent people who fit the profile. But because that strategy would be difficult to implement, Press says that mathematically, the more sensible method is not to profile at all. The study appears in the February 10 Proceedings of the National Academy of Sciences USA.

John Matson is a former reporter and editor for Scientific American who has written extensively about astronomy and physics.

More by John Matson
Scientific American Magazine Vol 300 Issue 4This article was published with the title “Math against Profiling” in Scientific American Magazine Vol. 300 No. 4 (), p. 31
doi:10.1038/scientificamerican0409-31b

Subscribe to Support Independent Journalism

Great science journalism requires human expertise, time, effort and creativity. And it costs money. That’s why I and the journalists here at Scientific American hope you’ll join our community.

When you subscribe, you are supporting staff and freelance journalists who are passionate about telling science stories that are true, important and compelling. Our editors and reporters are often experts in their fields, which means they understand the nuances of big discoveries and can untangle the breakthroughs from the hype. With a subscription, you are also supporting rigorous fact-checking to ensure the words we publish are precise and accurate. And you’re supporting original illustrations, graphics and photos that bring you closer to an advanced laboratory, an ice sheet in Antarctica or a space mission in orbit. You’re helping us craft other types of high-quality journalism as well: Our newsletters are carefully written, edited and curated by staffers you have or will come to know and love. Our Science Quickly podcast is based on original reporting, collaboration with editors and scientists and exacting production.

Subscriptions keep this engine running so we can continue to deliver thoughtful, rigorous and independent science journalism to you. In an era of viral misinformation, this work is crucial. If you value what we do, I hope you’ll consider joining us as a subscriber

Thank you,

Jeanna Bryner, Editor in Chief, Scientific American

Subscribe