Willingness to sacrifice for one's own group and hostility toward outsiders are proposed to have evolved together, each making the other viable.
Choi and Bowles modelled in 2007 whether altruism toward the group could survive without hostility toward outsiders, and found that neither trait was stable alone while the pair was. The uncomfortable implication is that the generosity and the hostility are not opposite dispositions but one package, which is why appeals to the first often strengthen the second.
In practice
- A fundraising campaign built on what our people owe each other raises more and hardens the boundary it raised it across.
- A department's strongest internal solidarity appears in the quarter it is competing with another department.
- Possible explanations
- The proposed explanation is coevolution: sacrifice for the group is costly and hard to sustain alone, and hostility to outsiders is costly too, but together they raise the group's success in conflict enough for both to spread.
- In its favour
- The models are explicit, and experimental work does find in-group generosity and out-group hostility correlated in the same individuals, which the theory predicts.
- Against it
- The argument rests substantially on simulation and on contested assumptions about how frequent and lethal ancestral intergroup conflict was, and the correlation could arise from a single tendency to favour the in-group rather than from two coevolved traits.
- Standing
- The coevolution argument rests substantially on simulation and on contested assumptions about ancestral intergroup conflict.
- Further reading
- Wikipedia
- Subject
- Sociology & Culture
- Essay
- How societies hold together, sort people, and change