Singh proposes a plausible account for the emergence of shamanism in which the desire of agents to influence events drives cultural evolutionary processes in domains with unpredictable, fitness-relevant outcomes. No other domain of behavior is perhaps costlier than warfare, which likely had large selective consequences in human evolution and for which success is often uncertain (Glowacki et al. Reference Glowacki, Wilson and Wrangham2017; Rusch Reference Rusch2014). Singh's account points the way toward understanding two features common to warfare in many small-scale societies: first, the prevalence of behaviors that are often ritualized and aimed at controlling unseen forces, enabling warriors to overcome fear; and second, the development of a class of ritual specialists for warfare that are distinct from war leaders and who often do not participate in conflict themselves.
The outcome of war is uncertain, and failure may result in the loss of one's life. Fear commonly accompanies anticipation of conflict, both in contemporary militaries and among warriors of small-scale acephalous societies (Bell Reference Bell1935; Chagnon Reference Chagnon1977; Goldschmidt Reference Goldschmidt, Rubinstein and Foster1994). Although cultural systems contribute to incentivizing participation (Glowacki & Wrangham Reference Glowacki and Wrangham2013; Zefferman & Mathew Reference Zefferman and Mathew2015), humans also adopt superstitious beliefs and behaviors to overcome anxiety and fear and increase self-confidence. Warriors in numerous societies carry amulets or use drugs and alcohol to mitigate fear (Goldschmidt Reference Goldschmidt, Rubinstein and Foster1994). With astonishing frequency, many of these interventions purport to make enemies unable to see or harm the warrior. For example, Tanga warriors of Papua New Guinea who carried a sprig of ginger around their necks were “coated in a suit of magic armour which neither axe nor spears … could penetrate” (Bell Reference Bell1935, p. 269), and Lakota participating in the Ghost Dance who wore “spirit shirts” were bulletproof (Bearor Reference Bearor2011). Soldiers in the Democratic Republic of the Congo rub emollients on their bodies to “make the bullets bounce off them” (Gettleman Reference Gettleman2012). Nyangatom warriors in Ethiopia preparing for battle blow smoke on each other, believing that the enemy will not see them (Glowacki Reference Glowacki2015), while among the Pokot of Kenya, spells are cast on the sandals of warriors to make their tracks invisible (Bollig & Osterle Reference Bollig, Österle, Rao, Bollig and Böck2007).
Saliently, many societies also have prewar collective dances (Goldschmidt Reference Goldschmidt, Rubinstein and Foster1994) such as the Maori Haka, now better known for its role in sporting events. These synchronistic dances often include acting out elements of combat such as mock shooting and fighting, and the lyrics frequently contain descriptions of previous exploits, the shame that befell cowards, or incantations for success such as “let all my enemies stand fixed … Let my hand go … true to the wounding” (Bell Reference Bell1935, pp. 268–70). Among the Nyangatom and Toposa, some participants in war dances fall into a trance state that functions as a signal of the warriors' braveness and eagerness to fight. Although one outcome of group synchronistic activities may be group bonding or fusion (Tarr et al. Reference Tarr, Launay and Dunbar2014), another less conspicuous function may be heightened self-confidence (similar to the effect of superstitions), reducing the incapacitating effects of fear and making success in combat more likely.
Although behaviors such as carrying talismans and observing ritual prohibitions (including refraining from sex) may occur without the intervention of ritual experts, warfare is a domain in which ritual specialists distinct from shamans are common. For example, the Pokot seek out ritual specialists who bless their guns (Bollig & Osterle Reference Bollig, Österle, Rao, Bollig and Böck2007), whereas among the Turkana and Nyangatom, ritual specialists sleep with rocks or bullets next to their head so the enemy will not wake (Glowacki Reference Glowacki2015; Gulliver Reference Gulliver1951). Unlike war leadership, which is common even in small-scale societies (Glowacki & von Rueden Reference Glowacki and von Rueden2015; Glowacki et al. Reference Glowacki, Isakov, Wrangham, Mcdermott, Fowler and Christakis2016), ritual leaders frequently do not accompany warriors to battle; instead, they provide interventions before and after combat. One striking difference between war ritual specialists and shamans is that the former in many societies do not have the barriers to entry that shamans do, including long initiations or non-human features. This shows that the uncertainty of war can drive the use of superstitious interventions and the emergence of specializations without key elements of shamanism, raising questions about what additional features mediate the cultural evolution of shamanism.
Because warfare can produce group-functional benefits, cultural evolutionary processes may be especially acute, driving increased selection for behaviors that appear to induce success. Success in war may contribute to the rapid spread of those traits within and between groups, which is one reason many war rituals look similar despite groups' diverse origins.
The success of war ritual specialists can also drive the evolution of social complexity toward increasing centralization and hierarchy. War ritual specialists usually collect fees or a share of the spoils (Ellis Reference Ellis1951; Lamphear Reference Lamphear, Fukui and Markakis1994), contributing to their wealth and influence. Insofar as the group is successful because of the actual or perceived intervention of the specialist, this may influence the social organization of the society as the ritual leader amasses wealth and power (Brown Reference Brown1979). For example, among the Turkana in the 1800s, ritual specialists held minor influence until the unprecedented success of Lokerio, a ritual leader in campaigns against neighboring groups. Turkana success alongside Lokerio's increasing wealth and influence resulted in the war diviner role becoming a powerful post and centralizing authority, “transforming his office into a new form … whose authority extended throughout every section of Turkana” (Lamphear Reference Lamphear, Fukui and Markakis1994, p. 74). This resulted in a new “collective identity” and “primordial nationalism” (Lamphear Reference Lamphear, Fukui and Markakis1994, p. 88).
The cultural evolutionary processes outlined by Singh are informative for understanding the suite of cultural practices that accompany war across human societies. Superstitions and rituals can promote self-confidence, dampen fear, and improve the likelihood of success at individual and group levels. They also can support ritual specialization, which, in some instances, qualitatively shapes social complexity. When scaled up, these processes explain why some groups succeed where others fail, especially in the domain of intergroup conflict.
Singh proposes a plausible account for the emergence of shamanism in which the desire of agents to influence events drives cultural evolutionary processes in domains with unpredictable, fitness-relevant outcomes. No other domain of behavior is perhaps costlier than warfare, which likely had large selective consequences in human evolution and for which success is often uncertain (Glowacki et al. Reference Glowacki, Wilson and Wrangham2017; Rusch Reference Rusch2014). Singh's account points the way toward understanding two features common to warfare in many small-scale societies: first, the prevalence of behaviors that are often ritualized and aimed at controlling unseen forces, enabling warriors to overcome fear; and second, the development of a class of ritual specialists for warfare that are distinct from war leaders and who often do not participate in conflict themselves.
The outcome of war is uncertain, and failure may result in the loss of one's life. Fear commonly accompanies anticipation of conflict, both in contemporary militaries and among warriors of small-scale acephalous societies (Bell Reference Bell1935; Chagnon Reference Chagnon1977; Goldschmidt Reference Goldschmidt, Rubinstein and Foster1994). Although cultural systems contribute to incentivizing participation (Glowacki & Wrangham Reference Glowacki and Wrangham2013; Zefferman & Mathew Reference Zefferman and Mathew2015), humans also adopt superstitious beliefs and behaviors to overcome anxiety and fear and increase self-confidence. Warriors in numerous societies carry amulets or use drugs and alcohol to mitigate fear (Goldschmidt Reference Goldschmidt, Rubinstein and Foster1994). With astonishing frequency, many of these interventions purport to make enemies unable to see or harm the warrior. For example, Tanga warriors of Papua New Guinea who carried a sprig of ginger around their necks were “coated in a suit of magic armour which neither axe nor spears … could penetrate” (Bell Reference Bell1935, p. 269), and Lakota participating in the Ghost Dance who wore “spirit shirts” were bulletproof (Bearor Reference Bearor2011). Soldiers in the Democratic Republic of the Congo rub emollients on their bodies to “make the bullets bounce off them” (Gettleman Reference Gettleman2012). Nyangatom warriors in Ethiopia preparing for battle blow smoke on each other, believing that the enemy will not see them (Glowacki Reference Glowacki2015), while among the Pokot of Kenya, spells are cast on the sandals of warriors to make their tracks invisible (Bollig & Osterle Reference Bollig, Österle, Rao, Bollig and Böck2007).
Saliently, many societies also have prewar collective dances (Goldschmidt Reference Goldschmidt, Rubinstein and Foster1994) such as the Maori Haka, now better known for its role in sporting events. These synchronistic dances often include acting out elements of combat such as mock shooting and fighting, and the lyrics frequently contain descriptions of previous exploits, the shame that befell cowards, or incantations for success such as “let all my enemies stand fixed … Let my hand go … true to the wounding” (Bell Reference Bell1935, pp. 268–70). Among the Nyangatom and Toposa, some participants in war dances fall into a trance state that functions as a signal of the warriors' braveness and eagerness to fight. Although one outcome of group synchronistic activities may be group bonding or fusion (Tarr et al. Reference Tarr, Launay and Dunbar2014), another less conspicuous function may be heightened self-confidence (similar to the effect of superstitions), reducing the incapacitating effects of fear and making success in combat more likely.
Although behaviors such as carrying talismans and observing ritual prohibitions (including refraining from sex) may occur without the intervention of ritual experts, warfare is a domain in which ritual specialists distinct from shamans are common. For example, the Pokot seek out ritual specialists who bless their guns (Bollig & Osterle Reference Bollig, Österle, Rao, Bollig and Böck2007), whereas among the Turkana and Nyangatom, ritual specialists sleep with rocks or bullets next to their head so the enemy will not wake (Glowacki Reference Glowacki2015; Gulliver Reference Gulliver1951). Unlike war leadership, which is common even in small-scale societies (Glowacki & von Rueden Reference Glowacki and von Rueden2015; Glowacki et al. Reference Glowacki, Isakov, Wrangham, Mcdermott, Fowler and Christakis2016), ritual leaders frequently do not accompany warriors to battle; instead, they provide interventions before and after combat. One striking difference between war ritual specialists and shamans is that the former in many societies do not have the barriers to entry that shamans do, including long initiations or non-human features. This shows that the uncertainty of war can drive the use of superstitious interventions and the emergence of specializations without key elements of shamanism, raising questions about what additional features mediate the cultural evolution of shamanism.
Because warfare can produce group-functional benefits, cultural evolutionary processes may be especially acute, driving increased selection for behaviors that appear to induce success. Success in war may contribute to the rapid spread of those traits within and between groups, which is one reason many war rituals look similar despite groups' diverse origins.
The success of war ritual specialists can also drive the evolution of social complexity toward increasing centralization and hierarchy. War ritual specialists usually collect fees or a share of the spoils (Ellis Reference Ellis1951; Lamphear Reference Lamphear, Fukui and Markakis1994), contributing to their wealth and influence. Insofar as the group is successful because of the actual or perceived intervention of the specialist, this may influence the social organization of the society as the ritual leader amasses wealth and power (Brown Reference Brown1979). For example, among the Turkana in the 1800s, ritual specialists held minor influence until the unprecedented success of Lokerio, a ritual leader in campaigns against neighboring groups. Turkana success alongside Lokerio's increasing wealth and influence resulted in the war diviner role becoming a powerful post and centralizing authority, “transforming his office into a new form … whose authority extended throughout every section of Turkana” (Lamphear Reference Lamphear, Fukui and Markakis1994, p. 74). This resulted in a new “collective identity” and “primordial nationalism” (Lamphear Reference Lamphear, Fukui and Markakis1994, p. 88).
The cultural evolutionary processes outlined by Singh are informative for understanding the suite of cultural practices that accompany war across human societies. Superstitions and rituals can promote self-confidence, dampen fear, and improve the likelihood of success at individual and group levels. They also can support ritual specialization, which, in some instances, qualitatively shapes social complexity. When scaled up, these processes explain why some groups succeed where others fail, especially in the domain of intergroup conflict.