The "Majority Illusion" in Social Networks

PLoS One. 2016 Feb 17;11(2):e0147617. doi: 10.1371/journal.pone.0147617. eCollection 2016.


Individual's decisions, from what product to buy to whether to engage in risky behavior, often depend on the choices, behaviors, or states of other people. People, however, rarely have global knowledge of the states of others, but must estimate them from the local observations of their social contacts. Network structure can significantly distort individual's local observations. Under some conditions, a state that is globally rare in a network may be dramatically over-represented in the local neighborhoods of many individuals. This effect, which we call the "majority illusion," leads individuals to systematically overestimate the prevalence of that state, which may accelerate the spread of social contagions. We develop a statistical model that quantifies this effect and validate it with measurements in synthetic and real-world networks. We show that the illusion is exacerbated in networks with a heterogeneous degree distribution and disassortative structure.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Humans
  • Illusions*
  • Normal Distribution
  • Social Networking*

Grants and funding

This work was supported in part by Air Force Office of Scientific Research (contract FA9550-10-1-0569), by the National Science Foundation (grant CIF-1217605) and by Defense Advanced Research Projects Agency (contract W911NF-12-1-0034). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.