Male-biased operational sex ratios and the Viking phenomenon: an evolutionary anthropological perspective on Late Iron Age Scandinavian raiding

Ben Raffield, Neil Price, Mark Collard

Research output: Contribution to journalArticlepeer-review

28 Citations (Scopus)
15 Downloads (Pure)


In this paper we use a combination of evolutionary theory, ethnographic data, written sources, and archaeological evidence to develop a new explanation for the origins of Viking raiding. Our argument focuses on the operational sex ratio, which is the ratio of males to females in a society who are ready to mate at a given time. We propose that a combination of two practises—polygyny and concubinage—and the increase in social inequality that occurred in Scandinavia during the Late Iron Age resulted in a male-biased Operational Sex Ratio. This would have created a pool of unmarried men motivated to engage in risky behaviours that had the potential to increase their wealth and status, and therefore their probability of entering the marriage market. With high-status men looking to instigate expeditions to acquire plunder and develop their reputations as war leaders, raiding represented a mutually beneficial means of achieving social advancement and success.
Original languageEnglish
Pages (from-to)315-324
Number of pages10
JournalEvolution and Human Behavior
Issue number3
Early online date30 Oct 2016
Publication statusPublished - May 2017

Bibliographical note

We would like to thank Laura Whitehouse, John Carman, Oliver Grimm, Julie Lund, Bjørnar Olsen, two anonymous reviewers, and the editor for their comments and suggestions on earlier versions of this paper. We also thank Alex Woolf for providing us with a copy of his forthcoming article on the Vikings in Ireland. Lastly, we are grateful to Luke Glowacki, Shane McFarlane, and Ryan Schacht for their insights about raiding and OSRs. Needless to say, all remaining errors are our own.

BR and MC are supported by the Social Sciences and Humanities Research Council of Canada through a Partnership Grant (895-2011-1009) awarded to the Cultural Evolution of Religion Research Consortium (www.ubc/hecc/cerc). MC is also supported by the Canada Research Chairs Program, the Canada Foundation for Innovation, the British Columbia Knowledge Development Fund, and Simon Fraser University. NP is supported by a Swedish Research Council grant for "The Viking Phenomenon" project (2015-00466).


  • Vikings
  • Late Iron Age Scandinavia
  • raiding
  • polygyny
  • concubinage
  • Operational Sex Ratio
  • male-male competition


Dive into the research topics of 'Male-biased operational sex ratios and the Viking phenomenon: an evolutionary anthropological perspective on Late Iron Age Scandinavian raiding'. Together they form a unique fingerprint.

Cite this