Violence and climate change in the Jōmon period, Japan

<i>Cultural Identity and Intergroup Conflicts:</i>

“…The data investigated in the present article is from the Yayoi period, when people mainly engaged in rice farming. Some are skeptical about the evolutionary scenario in the parochial altruism model based on the data obtained from the intergroup conflicts the prehistoric hunter-gatherers (e.g., Ferguson, 2013;Fry & Söderberg, 2013;Nakao et al, 2016Nakao et al, , 2020Nakao, Tamura, & Nakagawa, 2022). Although the question of how and when the outgroup hate and ingroup favor evolved remains unsolved, the present results suggested that the model is possibly applied to intergroup conflicts or warfare after the introduction of agriculture.…”

“…Bowles (2009) and Gintis & Bowles (2011) claimed that intergroup conflicts or warfare in prehistoric hunter-gatherer societies was an essential selective pressure for group selection of the out-/in-group biases. These claims have been challenged in many ways (e.g., Ferguson, 2013;Fry & Söderberg, 2013;Nakao et al, 2016Nakao et al, , 2020Nakao, Tamura, & Nakagawa, 2022) though controversies remain.…”

“…The model would expect that people show more out-group hate and in-group favor when warfare occurs than when it does not. The northern Kyushu area, especially the Mikuni Hills of the Middle Yayoi period, found clearer and richer evidence of warfare (i.e., injured skeletal remains) than other areas and periods (e.g., Nakagawa et al, 2021;Nakao et al, 2016Nakao et al, , 2020. If the model is accurate, out-group hate and in-group favor could be reflected in the archaeological remains, such as pottery making; the more frequent intergroup conflicts are, and the more opposed each group is (related to higher out-group hate), the more independent and coherent each group is and the more evident and more distinctive cultural identity (related to higher ingroup favor) could be established within each group (e.g., Nakao, Tamura, & Nakagawa, 2022).…”

Population pressure and prehistoric violence in the Yayoi period of Japan

“…The subsistence strategy in the Yayoi period (800 cal BC to AD 250 CE), wet rice cultivation, was introduced by immigrants from the Korean peninsula along with weapons such as stone arrowheads and daggers, resulting in enclosed settlements accompanied by warfare or large-scale inter-group violence (e.g., Sahara 1986;Nakahashi 2005;Hashiguchi 2007;Matsugi 2007;Terasawa 2000). As indicated by recent exhaustive surveys of skeletal remains in Japan (Nakao et al, 2016(Nakao et al, , 2020Nakagawa et al, 2017), this represents a significant increase in the frequency of violence compared with the population of the preceding Jomon period, pottery makers who followed a complex hunter-gatherer lifestyle and exhibited low levels of mortality due to conflict, in contrast with anthropological and ethnographical studies arguing the ubiquity of inter-group violence among present and prehistoric hunter-gatherers (e. g., Keeley 1996;LeBlanc 2003;Bowles 2009;Frayer and Martin 1997;Allen and Allen 2006;Allen and Jones 2014;Schwitalla et al, 2014;Lahr et al, 2016). The number of skeletal remains with trauma out of the total samples is 23 out of 2576 for the Jomon period and 100 out of 3298 for the Yayoi period.…”