https://doi.org/10.1177/0731121419835507 Sociological Perspectives 1–20 © The Author(s) 2019 Article reuse guidelines: sagepub.com/journals-permissions DOI: 10.1177/0731121419835507 journals.sagepub.com/home/spx Article Selection versus Socialization? Interrogating the Sources of Secularity in Global Science Daniel Bolger 1 , Robert A. Thomson Jr. 1 , and Elaine Howard Ecklund 1 Abstract Science and secularization have been linked in scholarship and the public imagination. Some suggest that scientific training leads to loss of religion. Yet there is only speculation about the processes by which scientists might become less religious and whether such processes are confined to the west or hold across national contexts. Using original survey data (N = 5,006) of biologists and physicists in India, Italy, and the United States, as well as 215 in-depth interviews, we examine the religious transitions of academic scientists and the factors that they say prompted their religious shifts. We find some support for work suggesting that scientific training is secularizing. Yet we also show that, across national contexts, the nonreligious disproportionately select into scientific careers. Furthermore, we find that scientists tend not to identify science as the primary factor in their own religious transitions. These results challenge long-held assumptions about the relationship between science and secularization. Keywords religion, science, secularization, cross-national, mixed methods Research on the religious lives of U.S. scientists finds that many are less likely than members of the general public to believe in God or identify with a religious tradition (Ecklund 2010; Larson and Witham 1998). Early research on this topic inferred that entry into scientific training began a process of individual-level secularization whereby scientific knowledge displaced religious belief (Leuba 1934). Such micro-level secularization was thought to foreshadow macro-level religious declines; that is, with increasing scientific advancement, collective religiosity declines (see Wilson 1966). Therefore, many scholars interested in the fate of religion have interrogated the religious beliefs of scientists, particularly elite scientists, as potential carriers of seculariza- tion (Ecklund and Long 2011). Recent research, however, problematizes over-simplified associations between increased sci- entific knowledge and religious decline. First, scientists are not universally irreligious; indeed, scientists are more religious than the general public in some international contexts (Ecklund et al. 2016). Second, scientists in the United States are more likely than the U.S. public to be raised in 1 Rice University, Houston, TX, USA Corresponding Author: Daniel Bolger, Department of Sociology, Rice University, MS-28, 6100 Main St., Houston, TX 77005, USA. Email: Dan.bolger@rice.edu 835507SPX XX X 10.1177/0731121419835507Sociological PerspectivesBolger et al. research-article 2019