War’s Enduring Effects on the Development of Egalitarian Motivations and In-Group Biases

Abstract

In suggesting that new nations often coalesce in the decades following war, historians have posed an important psychological question: Does the experience of war generate an enduring elevation in people's egalitarian motivations toward their in-group? We administered social-choice tasks to more than 1,000 children and adults differentially affected by wars in the Republic of Georgia and Sierra Leone. We found that greater exposure to war created a lasting increase in people's egalitarian motivations toward their in-group, but not their out-groups, during a developmental window starting in middle childhood (around 7 years of age) and ending in early adulthood (around 20 years of age). Outside this window, war had no measurable impact on social motivations in young children and had only muted effects on the motivations of older adults. These "war effects" are broadly consistent with predictions from evolutionary approaches that emphasize the importance of group cooperation in defending against external threats, though they also highlight key areas in need of greater theoretical development.

The effect of conflict history on cooperation within and between groups: Evidence from a laboratory experiment

“…While more research is needed to explore this issue, our ndings are also broadly consistent with eld experiments such as Gumen (2012) and Buchan et al (2009) who nd ingroup biases in similar designs using naturally-occurring group identities, as well as with previous work suggesting a link between parochialism and violent con ict (Choi and Bowles, 2007;Voors et al, 2012;Bauer et al, 2014). The fact that we nd a similar e ect in a neutrally-framed laboratory setting suggests that the mere act of competition over a xed-resource increases in-group bias, even in the absence of underlying ethnic divisions, cultural stereotyping, or exposure to violence.…”

“…In line with this theoretical prediction, recent empirical evidence on the e ects of war on social preferences shows that war leads to more altruism towards neighbors (Voors et al, 2012), stronger egalitarian norms towards in-group members by children (Bauer et al, 2014), and more within-group cooperation (Gneezy and Fessler, 2012).…”

Stress and the social brain: behavioural effects and neurobiological mechanisms

“…In one example, shortly after being challenged with a standardized laboratory stressor male participants took economic decisions indicative of increased trust, trustworthiness, sharing 192 and altruistic punishment 193 . Other studies in civilian populations of countries engaged in war conflicts suggested that the well-known phenomenon of increased societal in-group cooperation in times of war might not be a direct, immediate reaction of the individuals but rather a result of group pressure 194 and early life programming 195 .…”

The Impact of Violence on Individual Risk Preferences: Evidence from a Natural Experiment

“…Miguel and Roland 2011). In fact, several studies have found that exposure to civil conflict increases political engagement (Bellows andMiguel 2009, Blattman 2009), enhances cooperation and pro-sociality (Voors, Nillesen, Verwimp, Bulte, Lensink, andVan Soest 2012, Bauer, Cassar, Chytilová, andHenrich 2013), and makes people more willing to bear profitable risks (Voors, Nillesen, Verwimp, Bulte, Lensink, andVan Soest 2012, Callen, Isaqzadeh, Long, andSprenger 2014).…”