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We generalize DeGroot\u2019s model to account for a phenomenon well known in social psychology as biased assimilation: When presented with mixed or inconclusive evidence on a complex issue, individuals draw undue support for their initial position, thereby arriving at a more extreme opinion. We show that in a simple model of homophilous networks, our biased opinion formation process results in polarization if individuals are sufficiently biased. In other words, homophily alone, without biased assimilation, is not sufficient to polarize society. Quite interestingly, biased assimilation also provides a framework to analyze the polarizing effect of Internet-based recommender systems that show us personalized content.<\/jats:p>","DOI":"10.1073\/pnas.1217220110","type":"journal-article","created":{"date-parts":[[2013,3,28]],"date-time":"2013-03-28T00:28:38Z","timestamp":1364430518000},"page":"5791-5796","update-policy":"https:\/\/doi.org\/10.1073\/pnas.cm10313","source":"Crossref","is-referenced-by-count":384,"title":["Biased assimilation, homophily, and the dynamics of polarization"],"prefix":"10.1073","volume":"110","author":[{"given":"Pranav","family":"Dandekar","sequence":"first","affiliation":[{"name":"Departments of aManagement Science and Engineering,"}]},{"given":"Ashish","family":"Goel","sequence":"additional","affiliation":[{"name":"Management Science and Engineering and (by courtesy) Computer Science, and"}]},{"given":"David T.","family":"Lee","sequence":"additional","affiliation":[{"name":"Electrical Engineering, Stanford University, Stanford CA 94305"}]}],"member":"341","published-online":{"date-parts":[[2013,3,27]]},"reference":[{"key":"e_1_3_3_1_2","doi-asserted-by":"publisher","DOI":"10.2307\/2131242"},{"key":"e_1_3_3_2_2","doi-asserted-by":"publisher","DOI":"10.2307\/2111445"},{"key":"e_1_3_3_3_2","doi-asserted-by":"publisher","DOI":"10.1002\/ncr.114"},{"key":"e_1_3_3_4_2","volume-title":"Polarized America: The Dance of Ideology and Unequal Riches","author":"McCarty N","year":"2006","unstructured":"N McCarty, KT Poole, H Rosenthal Polarized America: The Dance of Ideology and Unequal Riches (MIT Press, Cambridge, MA, 2006)."},{"key":"e_1_3_3_5_2","doi-asserted-by":"publisher","DOI":"10.1080\/0022250X.1971.9989794"},{"key":"e_1_3_3_6_2","doi-asserted-by":"publisher","DOI":"10.1086\/507856"},{"key":"e_1_3_3_7_2","doi-asserted-by":"crossref","unstructured":"C Brandt N Immorlica G Kamath R Kleinberg An analysis of one-dimensional Schelling segregation. 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