Abstract

Collective memories are precious resources for the society, because they contribute to strengthening the emotional bonding between community members, maintaining groups cohesion, and directing future behavior. Understanding the formation of the collective memories of emotional upheavals is important to a better comprehension of people's reactions and of the consequences on their psychological health. Previous studies investigated the effects of single traumatizing events, but few of them applied a quantitative approach to analyze the different psychological processes associated to the collective memories formation of upheavals on a large scale. This thesis explores the opportunities of applying quantitative methods to the study of collective memories in a collaborative environment such as the English Wikipedia. First, the presence of commemoration processes in Wikipedia articles and talk pages about traumatic events will be investigated through the analysis of edit activity patterns. Second, natural language processing techniques will be applied to detect differences in the collective representations of traumatic and non traumatic events, in the temporal focus of old and recent traumatic events, and in the representations of natural and human-made disasters. Third, the temporal evolution of language related to emotional, cognitive and social processes will be analyzed in the talk pages of two different emotional upheavals, the 2005 London bombings and the 2011 Egyptian revolution. The results will confirm the interpretation of Wikipedia as a global memory place, and highlight specific psychological processes related to the formation of collective memories of different types of traumatic events, opening the way to the quantitative study of collective memory formation in digital collaborative environments.