In 1900, renowned mathematician David Hilbert laid down a challenge to future generations: 23 handpicked mathematical problems, all difficult, all important, and all unsolved.Since then, countless mathematicians around the world have struggled to solve the 23 “Hilbert Problems.” To date, 10 have been fully solved, 11 are partly solved or simply cannot be solved, and two remain at large — and are asimportant today as they were in 1900. Most important, the pursuit of the solutions had a profound and fundamental influence on the roadmap for 20th century mathematics, testament to Hilbert’s foresight.Starting April 10, Harvard University will take Hilbert’s vision one step further, shifting his lens to a new field of inquiry: the social sciences. After a year and a half of joint planning with the nonprofit Indira Foundation, which initiated the effort and also provided financial support, the Division of Social Science in Harvard’s Faculty of Arts and Sciences will convene a symposium of multidisciplinary experts to propose and prioritize an analogous set of the world’s hardest unsolved problems in social science.“Hilbert’s approach is as applicable to the social sciences today as it was to mathematics over a century ago,” says Stephen M. Kosslyn, Harvard’s dean of social science and John Lindsley Professor of Psychology in Memory of William James.During the daylong symposium, which will be open to the public, a panel of experts from multiple universities will individually present what they believe to be the hardest unsolved problems in the social sciences, emphasizing both why the problems are hard and why they are important. At the end of the day the panelists will debate their proposals with each other and with the audience. Over the 45 days following the event, anyone from around the world will be able to view streaming video of the symposium, vote on the proposed problems, and, perhaps most important, submit additional problems for consideration and voting.The final votes will be used, in combination with the symposium proceedings, to develop a prioritized list to focus and inform research and policy directions, as well as funding support, in the future.Kosslyn will host the April 10 symposium. Speakers include:Peter S. Bearman, Jonathan Cole Professor of Social Science at Columbia University, director of Columbia’s Lazarsfeld Center for the Social Sciences, and co-director of the Health & Society Scholars Program. He was the founding director (2000-08) of the Institute for Social and Economic Research and Policy at Columbia, and a 2007 recipient of the National Institutes of Health Director’s Pioneer Award;Nick Bostrom, professor in the faculty of philosophy and at the James Martin 21st Century School at Oxford University, and director of Oxford’s Future of Humanity Institute. In 2009, he was named one of the “Top 100 Global Thinkers” by Foreign Policy Magazine;Susan Carey, Henry A. Morss Jr. and Elizabeth W. Morss Professor of Psychology and chair of the Department of Psychology at Harvard. In 2009 she received the American Psychological Association’s Distinguished Scientific Contribution Award and in 2008 received the David E. Rumelhart Prize. She is a fellow of the National Academy of Sciences and the American Academy of Arts and Sciences;Nicholas A. Christakis, professor of medical sociology and professor of medicine at Harvard Medical School, professor of sociology in Harvard’s Faculty of Arts and Sciences, and attending physician at the Harvard-affiliated Mount Auburn Hospital. In 2009 he was named by Time magazine as one of the 100 most influential people in the world;Niall C. D. Ferguson, Laurence A. Tisch Professor of History in Harvard’s Faculty of Arts and Sciences and William Ziegler Professor of Business Administration at Harvard Business School. He was named by Time magazine as one of the 100 most influential people in the world in 2004;James H. Fowler, associate professor of political science at the University of California, San Diego, and associate professor at the Center for Wireless and Population Health Systems at the California Institute for Telecommunications and Information Technology. He received the American Political Science Association’s “Emerging Scholar Award” (EPOVB section) in 2010;Roland G. Fryer, Robert M. Beren Professor of Economics at Harvard, faculty research fellow at the National Bureau of Economic Research, and director of the Educational Innovation Laboratory at Harvard. In 2009 he was named by The Economist as one of the eight top young economists in the world;Claudia Goldin, Henry Lee Professor of Economics at Harvard and director of the Development of the American Economy Program at the National Bureau of Economic Research. She is also a fellow of the National Academy of Sciences and the American Academy of Arts and Sciences, the Gilman Fellow of the American Academy of Political and Social Science, and formerly vice president of the American Economic Association and president of the Economic History Association;Gary King, Albert J. Weatherhead III University Professor, based in the Department of Government, at Harvard, professor in the Department of Biostatistics, and director of Harvard’s Institute for Quantitative Social Science. He is also a fellow of the American Statistical Association, the American Association for the Advancement of Science, and the American Academy of Arts and Sciences, and was formerly senior science adviser to the World Health Organization;Emily F. Oster, assistant professor of economics at the Booth School of Business at the University of Chicago, and a faculty research fellow at the National Bureau of Economic Research;Ann Swidler, professor of sociology at the University of California, Berkeley, and member of the Sociological Research Association. She was a Pulitzer Prize nominee in 1986, a recipient of the League of Women Voters Award for Distinguished Scholarship, and a recipient of the Meyers Center Award for the Study of Human Rights in North America;Nassim N. Taleb, Distinguished Professor of Risk Engineering at the Polytechnic Institute of New York University and Distinguished Research Scholar at the BT Centre for Major Programme Management at the Said Business School of Oxford University. He is also the bestselling author of “The Black Swan,” described as one of the 12 most influential books of the past 60 years, and in 2008-09 was one of the top five most-downloaded authors on the Social Science Research Network (SSRN);Richard J. Zeckhauser, Frank P. Ramsey Professor of Political Economy at the Harvard Kennedy School and a research associate at the National Bureau of Economic Research. He is also a consultant to the World Bank on global warming, a member of the OECD High Level Advisory Board on Financial Management of Large-Scale Catastrophes, a member of the World Economic Forum’s Global Agenda Council on the Mitigation of Natural Disasters, an elected member of the Institute of Medicine of the National Academy of Sciences, and a recipient of the Ronald H. Coase Prize of the University of Chicago Law School;“We applaud the efforts of Dean Kosslyn and his team in bringing this idea to realization over the past year and a half,” said Nicholas A. Nash, a member of the Indira Foundation, a Connecticut-based charitable organization dedicated to supporting programs that can make a difference in the fields of education, health care, and social welfare. “We are pleased with the momentum generated by this initiative, given its potential for large, sustainable, and broad-based benefits. Particularly exciting is the collaborative nature of the effort, already involving an impressive list of thought leaders.”In addition to being open to the public, the event will be recorded, Webcast, and archived at http://socialscience.fas.harvard.edu. The symposium will take place from 10 a.m. to 5 p.m. EDT in Room B103 of Harvard’s Northwest Science Building (52 Oxford St., Cambridge, Mass.). The event is free and open to the public, but seating is limited and on a first-come, first-served basis. For more information, see http://socialscience.fas.harvard.edu/hardproblems.