The extreme self-sacrificial behaviour found in suicide bombers and soldiers where they are even prepared to die for one another presents an evolutionary puzzle: how can a trait that calls for an individual to make the ultimate sacrifice, defending a group of people they are not related to, persist over evolutionary time? A new study, published in Nature's Scientific Reports and led by the University of Oxford, provides insight into the causes of self-sacrifice in violent conflicts around the world, from holy wars to gangland violence.
First author Professor Harvey Whitehouse, from the School of Anthropology, explains: 'The theory that sharing negative experiences produces powerful social bonds was initially inspired by my fieldwork among the tribes of Papua New Guinea, where warriors often went through extremely painful initiation rituals. Since then we’ve found these effects in a much wider range of groups, from Libyan insurgents to Americans affected by the Boston Marathon bombings. This new paper presents a mathematical model that might explain why shared suffering leads to such strong commitment to the group, alongside a very broad range of evidence from the real world.'
The paper, 'The evolution of extreme cooperation via shared dysphoric experiences', is published in Scientific Reports.