Whether upheld as heroic or reviled as terrorism, people have been willing to lay down their lives for the sake of their groups throughout history. Why? Previous theories of extreme self-sacrifice have highlighted a range of seemingly disparate factors, such as collective identity, outgroup hostility, and kin psychology. In this paper, I attempt to integrate many of these factors into a single overarching theory based on several decades of collaborative research with a range of special populations, from tribes in Papua (...) New Guinea to Libyan insurgents and from Muslim fundamentalists in Indonesia to Brazilian football hooligans. These studies suggest that extreme self-sacrifice is motivated by identity fusion, a visceral sense of oneness with the group, resulting from intense collective experiences (e.g., painful rituals or the horrors of frontline combat) or from perceptions of shared biology. In ancient foraging societies, fusion would have enabled warlike bands to stand united despite strong temptations to scatter and flee. The fusion mechanism has often been exploited in cultural rituals, not only by tribal societies but also in specialized cells embedded in armies, cults, and terrorist organizations. With the rise of social complexity and the spread of states and empires, fusion has also been extended to much larger groups, including doctrinal religions, ethnicities, and ideological movements. Explaining extreme self-sacrifice is not only a scientific priority but also a practical challenge as we seek a collective response to suicide, terrorism, and other extreme expressions of outgroup hostility that continue to bedevil humanity today. (shrink)

Research seeking to explain the perpetration of violence and atrocities by humans against other humans offers both social and individualistic explanations, which differ namely in the roles attributed to empathy. Prominent social models suggest that some manifestations of inter-human violence are caused by parochial attitudes and obedience reinforced by within-group empathy. Individualistic explanations of violence, by contrast, posit that stable intra-individual characteristics of the brain and personality of some individuals lead them to commit violence and atrocities. An individualistic explanation argues (...) that the chief cause of violence is the perpetrator’'s lack of empathy with the victim. To offer the rudiments of a critique of the individualistic approach, I critically examine a model stating that violence is caused by empathy erosion. Specifically, the discussion of the empathy-erosion model is applied to the case of honour-based violence, a type of violence known for its communal character. Building from prior enquiries into violence and social cognition, I argue that an empathy-erosion explanation of HBV is defective because it does not consider important cultural and historical enablers of violence. Finally, as an alternative to individualism, I propose a psychohistorical approach to HBV in the migration context. This alternative combines psychological and philosophical enquiry with historical and ethnographical analysis. The psychohistorical approach hypothesises that distinct processes of cultural learning of honour codes both scaffold HBV and modulate the perpetrators’ emotions and empathy. (shrink)