Monday, March 26, 2018

Population is the main driver of war group size and conflict casualties

Rahul C. Oka, Marc Kissel, Mark Golitko, Susan Guise Sheridan, Nam C. Kim and Agustín Fuentes, Population is the main driver of war group size and conflict casualties, PNAS December 11, 2017. 201713972; published ahead of print December 11, 2017.

Significance: Recent views on violence emphasize the decline in proportions of war groups and casualties to populations over time and conclude that past small-scale societies were more violent than contemporary states. In this paper, we argue that these trends are better explained through scaling relationships between population and war group size and between war group size and conflict casualties. We test these relationships and develop measures of conflict investment and lethality that are applicable to societies across space and time. When scaling is accounted for, we find no difference in conflict investment or lethality between small-scale and state societies. Given the lack of population data for past societies, we caution against using archaeological cases of episodic conflicts to measure past violence.

Abstract: The proportions of individuals involved in intergroup coalitional conflict, measured by war group size (W), conflict casualties (C), and overall group conflict deaths (G), have declined with respect to growing populations, implying that states are less violent than small-scale societies. We argue that these trends are better explained by scaling laws shared by both past and contemporary societies regardless of social organization, where group population (P) directly determines W and indirectly determines C and G. W is shown to be a power law function of P with scaling exponent X [demographic conflict investment (DCI)]. C is shown to be a power law function of W with scaling exponent Y [conflict lethality (CL)]. G is shown to be a power law function of P with scaling exponent Z [group conflict mortality (GCM)]. Results show that, while W/P and G/P decrease as expected with increasing P, C/W increases with growing W. Small-scale societies show higher but more variance in DCI and CL than contemporary states. We find no significant differences in DCI or CL between small-scale societies and contemporary states undergoing drafts or conflict, after accounting for variance and scale. We calculate relative measures of DCI and CL applicable to all societies that can be tracked over time for one or multiple actors. In light of the recent global emergence of populist, nationalist, and sectarian violence, our comparison-focused approach to DCI and CL will enable better models and analysis of the landscapes of violence in the 21st century.


  1. I would caution against using archeology or ethnography without noting the issues (an absence of hard evidence and the use of cultures that are not isolated from a larger modern world)

    I would however seriously encourage evo. psy. to get to the library more often and read more outside of its normal range.

    It engages in very selective reading and presentation of arguments. I don't disagree with the conclusions but some of the claims made my hair stand on end. What on earth is it reading?

    Its suspiciously selective and narrow in its discussion of the subject.

    Sober language seems to mask a somewhat melodramatic soul.

    This looks like a lets pretend what we are doing is scientific argument, which is a large part of the issue in archeology and the ethnography here.

  2. p.s I seriously agreed with the final conclusion of the analytical v.s continental philosophy article.

    An issue of analytical historical/ethnological arguments is an over- inflected striped down to the bone over- simplification of the issues.