Only 150 of Your Facebook Contacts Are Real Friends

Even with social media, we max out at 150 real relationships

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Humans are extremely social creatures. Anthropologists maintain that our hypersocial nature has helped us become a uniquely dominant species. Now social media allows a large percentage of people to communicate effortlessly worldwide (large graph), something no other animal can do.

Yet despite running up hundreds of friends on Facebook and thousands of followers on Twitter, we are fooling ourselves, scientists say. We can really only maintain about 150 meaningful relationships at any time. Study after study confirms that most people have about five intimate friends, 15 close friends, 50 general friends and 150 acquaintances (green bars). Robin Dunbar, an evolutionary psychologist now at the University of Oxford, who had showed this pattern convincingly in the 1990s, revisited his old conclusions in a recent study of several thousand Facebook users. He found that despite social media's explosion, our network of significant contacts still maxes out at around 150. This threshold is imposed by brain size and chemistry, as well as the time it takes to maintain meaningful relationships, Dunbar says. “The time you spend,” he adds, “is crucial.”

Credit: Jen Christiansen; Sources: International Telecommunication Union, World Telecommunication/ICT Development Report and Database (Internet use data); Pew Research Center (social media data); “Do Online Social Media Cut through the Constraints That Limit the Size of Offline Social Networks?” by R.I.M. Dunbar, in Royal Society Open Science, Vol. 3, Article No. 150292; January 2016 (Facebook friend survey data)

Mark Fischetti was a senior editor at Scientific American for nearly 20 years and covered sustainability issues, including climate, environment, energy, and more. He assigned and edited feature articles and news by journalists and scientists and also wrote in those formats. He was founding managing editor of two spin-off magazines: Scientific American Mind and Scientific American Earth 3.0. His 2001 article “Drowning New Orleans” predicted the widespread disaster that a storm like Hurricane Katrina would impose on the city. Fischetti has written as a freelancer for the New York Times, Sports Illustrated, Smithsonian and many other outlets. He co-authored the book Weaving the Web with Tim Berners-Lee, inventor of the World Wide Web, which tells the real story of how the Web was created. He also co-authored The New Killer Diseases with microbiologist Elinor Levy. Fischetti has a physics degree and has twice served as Attaway Fellow in Civic Culture at Centenary College of Louisiana, which awarded him an honorary doctorate. In 2021 he received the American Geophysical Union’s Robert C. Cowen Award for Sustained Achievement in Science Journalism. He has appeared on NBC’s Meet the Press, CNN, the History Channel, NPR News and many radio stations.

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Jen Christiansen is acting chief of design and senior graphics editor at Scientific American, where she art directs and produces illustrated explanatory diagrams and data visualizations. She is also author of the book Building Science Graphics: An Illustrated Guide to Communicating Science through Diagrams and Visualizations (CRC Press). In 1996 she began her publishing career in New York City at Scientific American. Subsequently she moved to Washington, D.C., to join the staff of National Geographic (first as an assistant art director–researcher hybrid and then as a designer), spent four years as a freelance science communicator and returned to Scientific American in 2007. Christiansen presents and writes on topics ranging from reconciling her love for art and science to her quest to learn more about the pulsar chart on the cover of Joy Division’s album Unknown Pleasures. She holds a graduate certificate in science communication from the University of California, Santa Cruz, and a B.A. in geology and studio art from Smith College. Follow Christiansen on Bluesky @jenchristiansen.com

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Scientific American Magazine Vol 319 Issue 3This article was published with the title “Peak Friends” in Scientific American Magazine Vol. 319 No. 3 (), p. 104
doi:10.1038/scientificamerican0918-104

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