Human Nature

, Volume 25, Issue 3, pp 359–377

The Two Sides of Warfare

An Extended Model of Altruistic Behavior in Ancestral Human Intergroup Conflict

DOI: 10.1007/s12110-014-9199-y

Cite this article as:
Rusch, H. Hum Nat (2014) 25: 359. doi:10.1007/s12110-014-9199-y


Building on and partially refining previous theoretical work, this paper presents an extended simulation model of ancestral warfare. This model (1) disentangles attack and defense, (2) tries to differentiate more strictly between selfish and altruistic efforts during war, (3) incorporates risk aversion and deterrence, and (4) pays special attention to the role of brutality. Modeling refinements and simulation results yield a differentiated picture of possible evolutionary dynamics. The main observations are: (a) Altruism in this model is more likely to evolve for defenses than for attacks. (b) Risk aversion, deterrence, and the interplay of migration levels and brutality can change evolutionary dynamics substantially. (c) Unexpectedly, one occasional simulation outcome is a dynamically stable state of “tolerated intergroup theft,” raising the question as to whether corresponding patterns also exist in real intergroup conflicts. Finally, possible implications for theories of the coevolution of bellicosity and altruism in humans are discussed.


Intergroup conflict Cooperation Public goods Altruism Warfare 

Supplementary material

12110_2014_9199_MOESM1_ESM.pdf (3.3 mb)
ESM 1(PDF 3.32 mb)

Copyright information

© Springer Science+Business Media New York 2014

Authors and Affiliations

  1. 1.Behavioral and Institutional Economics, JLU GiessenGiessenGermany

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