TY - JOUR
T1 - Humans reciprocate by discriminating against group peers
AU - Hugh-Jones, David
AU - Ron, Itay
AU - Zultan, Ro'i
PY - 2019/1
Y1 - 2019/1
N2 - Motivated by cycles of intergroup revenge in real-world conflicts, we experimentally test the hypothesis that humans practice group-based reciprocity: if someone harms or helps them, they harm or help other members of that person's group. Subjects played a trust game, then allocated money between other people. Senders whose partners returned more in the trust game gave more to that partner's group members. The effect was about half as large as the effect of direct reciprocity. Receivers' allocations to group members were not affected by their partners’ play in the trust game, suggesting that group reciprocity was only triggered by strong norm violations. We discuss the role of group reciprocity in conflict among early humans.
AB - Motivated by cycles of intergroup revenge in real-world conflicts, we experimentally test the hypothesis that humans practice group-based reciprocity: if someone harms or helps them, they harm or help other members of that person's group. Subjects played a trust game, then allocated money between other people. Senders whose partners returned more in the trust game gave more to that partner's group members. The effect was about half as large as the effect of direct reciprocity. Receivers' allocations to group members were not affected by their partners’ play in the trust game, suggesting that group reciprocity was only triggered by strong norm violations. We discuss the role of group reciprocity in conflict among early humans.
KW - Upstream reciprocity
KW - Group identity
KW - Intergroup conflict
UR - https://github.com/hughjonesd/group-reciprocity
UR - http://www.scopus.com/inward/record.url?scp=85053855069&partnerID=8YFLogxK
U2 - 10.1016/j.evolhumbehav.2018.08.005
DO - 10.1016/j.evolhumbehav.2018.08.005
M3 - Article
VL - 40
SP - 90
EP - 95
JO - Evolution and Human Behavior
JF - Evolution and Human Behavior
SN - 1090-5138
IS - 1
ER -