Please use this identifier to cite or link to this item: http://hdl.handle.net/1893/23310
Appears in Collections:Computing Science and Mathematics Journal Articles
Peer Review Status: Refereed
Title: The Effects of Extra-Somatic Weapons on the Evolution of Human Cooperation towards Non-Kin
Authors: Philips, Tim
Li, Jiawei
Kendall, Graham
Contact Email: lij@cs.stir.ac.uk
Issue Date: 5-May-2014
Publisher: Public Library of Science
Citation: Philips T, Li J & Kendall G (2014) The Effects of Extra-Somatic Weapons on the Evolution of Human Cooperation towards Non-Kin, PLoS ONE, 9 (5), Art. No.: e95742.
Abstract: Human cooperation and altruism towards non-kin is a major evolutionary puzzle, as is ‘strong reciprocity’ where no present or future rewards accrue to the co-operator/altruist. Here, we test the hypothesis that the development of extra-somatic weapons could have influenced the evolution of human cooperative behaviour, thus providing a new explanation for these two puzzles. Widespread weapons use could have made disputes within hominin groups far more lethal and also equalized power between individuals. In such a cultural niche non-cooperators might well have become involved in such lethal disputes at a higher frequency than cooperators, thereby increasing the relative fitness of genes associated with cooperative behaviour. We employ two versions of the evolutionary Iterated Prisoner's Dilemma (IPD) model – one where weapons use is simulated and one where it is not. We then measured the performance of 25 IPD strategies to evaluate the effects of weapons use on them. We found that cooperative strategies performed significantly better, and non-cooperative strategies significantly worse, under simulated weapons use. Importantly, the performance of an ‘Always Cooperate’ IPD strategy, equivalent to that of ‘strong reciprocity’, improved significantly more than that of all other cooperative strategies. We conclude that the development of extra-somatic weapons throws new light on the evolution of human altruistic and cooperative behaviour, and particularly ‘strong reciprocity’. The notion that distinctively human altruism and cooperation could have been an adaptive trait in a past environment that is no longer evident in the modern world provides a novel addition to theory that seeks to account for this major evolutionary puzzle.
Type: Journal Article
URI: http://hdl.handle.net/1893/23310
DOI Link: http://dx.doi.org/10.1371/journal.pone.0095742
Rights: © 2014 Phillips et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Affiliation: Independent
Computing Science - CSM Dept
University of Nottingham

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