The typical collective memories of societies involved in intractable conflicts play a major role in the eruption and continuation of the conflicts, whereas the positive transformation of these memories to being less self-serving promotes peacemaking. A major factor that inhibits such transformation is self-censorship. Self-censorship, practiced by members of a society's formal institutions, inhibits the dissemination of alternative, more accurate narratives of the conflict that may change dominating biased conflict-supporting memories. Despite the importance of formal self-censorship in maintaining collective memories of conflicts, little empirical and theoretical research has examined this phenomenon. The present study addresses this omission. It examines the self-censorship practiced from 1949 to 2004 in 3 formal Israeli institutions (the National Information Center, the IDF/army, and the Ministry of Education) regarding the main historical event of the Israeli-Palestinian conflict: the causes of the 1948 Palestinian exodus. This is done by analyzing all of these institutions' publications produced throughout the 56-year research period and interviewing their key position holders. The results show that the institution gatekeepers practiced self-censorship for 5 reasons: garnering international support, mobilizing citizens, the impact of Zionist ideology, institutional norms, and fear of sanctions. The empirical findings are used to elicit theoretical insights, such as a definition for formal self-censorship, the difference between self-censorship practiced by gatekeepers (from formal and informal institutions) and that practiced by ordinary individuals, the 5 reasons for such self-censorship RAFI NETS-ZEHNGUT was awarded his PhD at the Political Science Department at Tel Aviv University, and was a predoctoral fellow at Yale and Columbia Universities. Currently he is the Managing Director of the International Summer Program in Conflict Resolution at Bar-Ilan University, Israel. His research studies the socio-psychological aspects of conflicts (e.g., via transitional justice and reconciliation), with the main focus being on their collective memory. Regionally, he focuses on the Israeli-Arab/ Palestinian conflict. For more details see http://www .collective-memory.info/. RUTHIE PLISKIN is currently working towards a doctoral degree in Social Psychology at the School of Psychological Sciences at Tel Aviv University and at the Baruch Ivcher School of Psychology at the Interdisciplinary Center Herzliya, under the guidance of Eran Halperin, Daniel Bar-Tal, and Gal Sheppes. Her research focuses on the interrelations of emotional processes and ideology in intergroup conflict, and she is also interested more generally in the mechanisms underlying psychological barriers to intergroup conflict resolution. DANIEL BAR-TAL is Branco Weiss Emeritus Professor of Research in Child Development and Education at the School of Education, Tel Aviv University. His research interest is in political and social psychology studying so-cio...