Roger E. Kasperson is a research professor and distinguished scientist in the Graduate School of Geography at Clark University. He writes frequently about risk analysis, risk communication, global environmental change, risk and ethics, and environmental policy. Kasperson is a member of the National Academy of Sciences and the American Academy of Arts and Sciences. He has been honored by the Association of American Geographers for his hazards research and is a recipient of the 2006 Distinguished Achievement Award of the Society for Risk Analysis. He currently serves on the Human Dimensions of Global Change Committee and the Committee on Strategic Advice for the Climate Change Program of the US National Research Council, is co-chair of the scientific advisory committee of the Potsdam Institute for Climate Change, and is on the executive steering committee of the START Programme of the International Geosphere-Biosphere Programme. The conceptual framework described in this article was first presented in the journal Risk Analysis in 1988. For a full treatment of social amplification, see The Social Amplification of Risk, co-authored by Kasperson, Nick Pidgeon, and Paul Slovic (Cambridge University Press, 2003).