Turkana warriors’ call to arms: how an egalitarian society mobilizes for cattle raids

Abstract

Humans are able to overcome coordination and collective action problems to mobilize for large-scale intergroup conflict even without formal hierarchical political institutions. To better understand how people rally together for warfare, I examine how the politically decentralized Turkana pastoralists in Kenya assemble raiding parties. Based on accounts of 54 Turkana battles obtained from semi-structured interviews with Turkana warriors, I describe the precipitating factors, recruitment process, exhortations and leadership involved in marshalling a raiding party. Details of this ethnographic case shed light on how voluntary informal armies are mobilized, and illustrate how culturally evolved institutions harness our cooperative dispositions at multiple scales to produce large-scale warfare.

This article is part of the theme issue ‘Intergroup conflict across taxa’.

1. Introduction

Intergroup conflict in humans is evidently larger in scale and intensity than noted in any other mammal, despite uncertainties about how pervasive large-scale intense warfare has been across time and space [1–10]. It is useful to know which facets of our cooperative dispositions are necessary and sufficient to explain human warfare at different social scales, and how culturally evolved institutions interface with these dispositions to elicit actions that promote or curtail warfare. Like human cooperation more generally, our capacity to unite for warfare hinges on some combination of kinship and affinal ties [11,12], bonds between close associates [13–16], reputational benefits [17,18], social sanctioning of free riders [14,19,20], shared values [21,22], leadership [23,24] and hierarchical institutions [25,26]. However, the relative importance and the sufficiency of any one mechanism to account for such a phenomenal form of collaboration is debated. Some work suggests that strong close bonds between well-known individuals is what motivates self-sacrificial acts even in large-scale warfare [13,16]. Other work indicates that sanctions [19] or culturally evolved institutions such as formal hierarchical military institutions [25,26] are essential for building cohesion when combatants do not know each other previously. Some scholars have de-emphasized the importance of the cooperative dilemma of uniting for war and conceived of how participation may directly align with an individual's own interest [17,27]. In these accounts, group-level concerns may or may not align with, but are nonetheless subsidiary to, individual-level concerns. Alternately, group-structured cultural evolutionary processes could lead to institutions that amplify self-interested motives for participating in warfare [9].

Details of how humans conduct war in different societies can reveal the nature of the cooperative dilemma and what pathways are available to individuals, and to cultural evolutionary processes, to resolve it. Here I describe how a politically uncentralized pastoral society in Kenya, the Turkana, organizes for cattle raids against neighbouring pastoral groups. The Turkana practice semi-nomadic pastoralism in the semi-arid savannah habitats of northwest Kenya [28–30], relying on consumption and trade of livestock products for their subsistence. Linguistically they are part of the Karimojong Cluster, a Nilo-Saharan group that has its origins in north eastern Uganda, and currently also includes the Jie, Karimojong, Dodos and Teso of Uganda, Toposa of South Sudan and Nyangatom of Ethiopia [31,32]. Descending the rift escarpment from Uganda to Kenya, the Turkana have expanded approximately 400 km southward and 150 km eastward to occupy a substantive part of northern Kenya west of Lake Turkana over two centuries. They continue to experience population growth. In 2006, their population in Kenya was estimated at 451 000 [33], while the most recent census of 2019 estimates their population to be 1 016 174 [34].

Turkana society is organized around residence, descent and age. A household includes a married man and his wives, unmarried children and married sons who have not yet separated their livestock from their father's herds. Households that have set up camp together comprise a settlement. Settlements may be temporary mobile cattle camps, or semi-permanent camps that are occupied for most of the year by elders, women and young children. Because households make their migration decision independently [29], the composition of a settlement remains in flux. Residence is patrilocal, and clans are patrilineal descent groups. However, like other groups in the Karimojong Cluster, the Turkana reckon descent and maintain co-residence for only two to three generations [30,35]. This contrasts with some pastoral societies in which several generations of patrilineal kin live together and form a political unit. Instead, Turkana men are organized into age sets with other men born in the same 5–6 year period [35,36]. These groups of similar-aged men mobilize for action across clan and settlement boundaries [37]. Turkana territory is divided into 18 territorial sections—geographical regions within which herdsmen are free to graze anywhere. Relocation outside one's natal territorial section and shared use of pastures and water by multiple territorial sections occurs by mutual agreement of elders. Political or military authority is not centralized. Senior age-groups have decision-making privileges and arbitrate disputes. Settlement and age-group leaders command respect and have influence, but do not have coercive authority on their own.

The Turkana experience combat in offensive raids as well as in defence. Like their pastoral neighbours who launch raids on them, Turkana engage in two kinds of raids—stealth raids that involve a few men who aim to find poorly guarded livestock, or force raids that involve larger numbers of men who plan to engage in combat. As reported in Mathew & Boyd [19], a few hundred warriors (average of 315) are mobilized from multiple settlements, age groups and territorial sections. While stealth raids are relatively low risk, there is a 1% chance of being killed on average in a force raid, and larger expected payoffs with an average gain of 11 instead of three cows per participant. Cowardice and desertion are punished through voluntarily imposed informal third-party sanctions, ranging from verbal criticism to collective corporal punishment and fines. Raiding other Turkana is considered to be banditry and is strongly condemned.

In the study area, most of the raids were against the Toposa of South Sudan, followed by the Dodos of Uganda. These communities in turn initiate raids against the Turkana. Warfare accounts for approximately half of adult male mortality among Turkana herders occupying the border region, roughly evenly split between offensive raids and defence [19]. During periods of negotiated peace, elders from communities on both sides meet and agree to peacefully share grazing and water resources along their borders. At present these are often mediated by community-based organizations that bridge local pastoralist institutions with the nation state. Cross-border trade and intermarriage increase but peace is usually short-lived. Young men are tempted to use the lowered vigilance as an opportunity to steal poorly guarded cattle. Repeated losses to such stealth raids can motivate one side to justify launching a large offensive attack. Negotiations to return the raided animals may help to prolong the cease fire, but hostilities eventually resume. While Mathew & Boyd [19] focused on quantifying the costs and benefits of raids, the scale of cooperation and the role of peer sanctioning in maintaining cohesion on the raid, here I analyse and describe how large-scale raiding parties are mobilized. The descriptions illustrate how personal and communal motives, close bonds, normative expectations and leadership institutions intersect to produce a voluntary and willing army of men who trust their fellow combatants enough to risk their lives for a common cause.

To understand the informal cultural institutions that enable contemporary inter-ethnic cattle raiding, it is essential to note the long-standing traditions of warfare among East African pastoralists [29,31,32,38–41]. Internal violence tended to be strongly curtailed. For instance, the informal tribal policy in Karimojong society obliged members to fight other Karimojong with sticks, not spears, in the event of inter-personal conflict, and to not take other Karimojong's livestock, except for a rightful cause [32]. In Nuer tradition, the tribe was the largest political unit that is obliged to mobilize for warfare and within which there were obligations to settle conflicts without resorting to violence [38]. External war was a regular occurrence [42], and had a strong influence in shaping territorial boundaries. The Nuer expanded their territory fourfold, at the expense of Dinka in about 75 years [41]. The Maasai expanded in the last 200 years in large part through military means [24]. The Turkana, after breaking away from the territorial home of the proto-Karimojong group in Eastern Uganda, expanded into their current territory over a period of 150 years in part through raiding and warfare [30].

Some ethnographic accounts have highlighted the eagerness of warriors to join raids, while others have noted the challenges of marshalling a resistance. For instance, Evans-Pritchard [38, p. 126] writes of the Nuer, ‘Boys look forward to the day when they will be able to accompany their elders on these raids against the Dinka, and as soon as youths have been initiated into manhood they begin to plan an attack to enrich themselves and to establish their reputation as warriors.’ Thomas [40, p. 130] on the other hand discusses how the Dodos' struggled in the 1960s to muster a defence and the need for social sanctions to compel warriors. On one of the days that she was present among the Dodos, the alarm sounded through the blowing of a horn to warn of an attack, presumably by the neighbouring Turkana. Men with spears were walking two or three, assembling for defence. Thirty men had gathered where she was. One of them looked at the gathered men and said: ‘Someone is not here… We are needed elsewhere, perhaps others will join us. Let us not wait here.’ In her observation, many people were missing who should have been there, but the rest went to where they thought the Turkana attack should be coming from.

Age-based social organization is particularly important for marshalling for war in shallow-descent societies [32,35–37]. For example, age-based authority mediates the meting out of punishment and dispute resolution among the Karimojong where most punishment is by elders in the form of curses, and physical punishment is meted out by elders through the help of junior initiates who are recruited to beat the violator [32]. Aside from age sets, deep-descent segmentary lineages [38] and leadership [23,24] have been noted to be crucial in mobilizing for cattle raids.

Firearms proliferated through various pastoral communities in the area in the 1970s and 1980s, replacing spears as the traditional fighting weapon [43–45], and has led to a rise in commercial cattle raiding in some pastoral communities [43,44,46]. Since the spread of firearms, the impact of warfare on migration patterns and livestock management decisions [29], and health, fertility and mortality [47–49] have been assessed. The current study adds to this cumulative body of literature, and can help assess the degree of continuity in raiding traditions in these societies over the last few decades. However, the main goal of this study is to provide a dense description of how large raiding parties are mobilized without centralized and coercive leadership. As such, the current analysis does not focus on situating Turkana raiding within the larger historical and socio-political forces that has impacted cattle raiding in East Africa. I provide a brief description of how this study site fits within the typical patterns of change, but detailed analyses of these larger-scale shifts have been done by other authors [29,50–53].

2. Methods

The data were collected during 9.5 months of fieldwork in 2008–2010. Adult men reliant primarily on pastoralism for their livelihood were recruited by trained local Turkana research assistants in a town close to the ethnic border frequented by nomadic Turkana who live in the surrounding 50 km radius. Participants were compensated for their time with 500 Kenyan Shillings for the interviews, which lasted 3–6 h. In addition to demographic questions and vignette studies, semi-structured interviews were conducted to reconstruct the history of subject's participation in offensive and defensive raids. Based on this chronological ordering, subjects were then asked questions to elicit a detailed account of the most recent offensive raid the subject had joined, which provided the basis for the synthesis given here. The time since this particular raid varied from a few days or weeks, to a few years, depending on the subject's age and raiding frequency. Questions were framed by the researcher, the research assistant (RA) then asked the participant the question in Turkana, and translated the participant's response immediately to the researcher, before the next question was asked. A digital recording of each participant's response was also obtained and a fraction of these was translated independently by another local RA. Gaps in the first translation were filled using the second translation from the digital recording when possible. The analysis presented here is based on accounts of 54 force raids. All data stem from interviews of raids that had already transpired, and no raids were observed in the conducting of the study. The study protocol was approved by the University of California Los Angeles Institutional Review Board. Since most participants were not literate, consent was given verbally with an approved consent script. Undergraduate RAs, who were anthropology majors from the University of California Los Angeles, assisted in coding the data by reading through the detailed descriptions to find and group text that pertains to pre-identified themes, and noting the presence or absence of variables of interest. The methods are described in more detail in the electronic supplementary material of Mathew & Boyd [19].

3. Results

(a) . How raids are initiated

A raid is initiated when one or more people propose that it is time for the Turkana to launch an attack on the ‘ngimoe’, which means foreigners or non-Turkana persons and is synonymous with enemies. Large raids are most often called by diviners—people who are thought to have the ability to foresee future outcomes, but the process can also be set in motion by any Turkana man—a victim of a raid, well-known warriors, leaders of settlements or an age group (figure 1). Small groups of young men who have recently ventured into enemy territory for stealth raids may have acquired detailed knowledge about the enemy's whereabouts and detected a strategic opportunity for a large raid. Men out on a hunting expedition may have observed that a large enemy settlement has just moved close to the border making them easily accessible. Herdsman out in the grazing fields, patrolling for enemy scouts, may have noted that the enemy has settled in territory typically used by Turkana. A particular age group or the leader of a settlement, or well-known warriors may simply decide that it has been long since the Turkana have gone on a raid, and therefore it's time to go and bring animals so that people may be fed. Raids can be initiated during the wet season and the dry season. During the wet season, when households settle in preferred interior parts of their territory, herding duties are less strenuous, leaving herdsmen with more time for other activities, including raiding. In the dry season, herding duties are more demanding, but herders are vying for and occupying limited grazing lands along border regions bringing them closer to neighbouring ethnic groups.

Figure 1.

Initiator. Frequency of raids initiated by diviners, people from another settlement, ordinary folks (individuals), settlement leaders, gathering of men having a discussion (ourselves) and famous warriors. N = 49. (Online version in colour.)

This nascent idea for a raid will then be presented informally to others—age-mates, elders or leaders. If the idea gains traction, the initiators of the raid announce their plan within their local settlement. Discussions ensue in which the opinions of the larger set of men from the local settlement get voiced. There are preliminary deliberations about the best size of the raiding party and consequently whether men from other settlements and territorial sections need to be mobilized. Decisions are made about how widely word should be sent out, and to which other settlements and territorial sections. Messengers are then sent to chosen settlements both within the home territorial section and beyond to announce the news and to request that these settlements send men. Meetings ensue in which messengers relay a brief plan to the leaders and elders or to their corresponding age-group members. Subsequently, individuals who are convinced to join, will invite and encourage their close friends, cousins, in-laws, trusted raiding companions and local age-mates to join. Word spreads in this fashion and gradually men will trickle into the settlement that has initiated the raid. A large raiding party with men from different territorial sections, age groups and settlements thus materializes.

(b) . Motives

The main goal of large-scale offense raids is to acquire livestock, but retaliation, favourable divinations, proximity of enemy and incursions are important for precipitating the event (figure 2). One informant said that he joined a raid because a neighbouring ethnic group had just raided the Turkana. He did not lose any animals, but said that his brother-in-law lost his, and added, that even if it is not your family, that these people are Turkana like him, and so he has to fight back. Although rare, in one raid, the main goal was revenge, not animals. The raid was initiated quickly after a settlement was attacked so that the enemy would know this attack was retaliation for that raid. In another, warriors set out knowing that they were not likely to acquire animals, and though they returned empty handed they considered the raid a success because they could inflict harm on their opponents, who had recently raided them. Young men who are venturing out on cattle-stealing or game-hunting missions may find a strategically well-positioned enemy settlement with abundant livestock. They report back to their settlement and the prospect of acquiring animals instigates men to mobilize. Raids may also be initiated to displace enemy settlements that have settled around watering holes or grazing areas considered to be part of Turkana territory. The precipitating event for one of the largest raids in the sample was a hunter's discovery that herders from another ethnic group had settled at a watering site that is typically used by the Turkana. The stated goal was to drive them away from Turkana territory and settle there themselves. Feelings of anger and a desire to avenge the loss of lives and livestock the Turkana have suffered serially in the hands of the enemy is almost always channelled into the justification for a raid even when it is not the initial crystallizing factor.

Figure 2.

Motives. (a) Main motives for calling for a raid (n = 37). (b) Main motives for subject to join the raid (n = 42). ‘Animals’ denotes desire for or possibility of gaining livestock on the raid. ‘Peers’ refers to being motivated or pressured to join because one's peers were joining. ‘Kin’ denotes a raid in which persuasion by nephew who needed animals prompted subject to join. (Online version in colour.)

The strongest personal motivation for men to join a raid is to gain animals (figure 2). This is compounded by the fact that many others in their age group are planning to join. Age-mates entice their friends to join with the prospect of a successful raid. They remind them of the cattle that can be had if they join this raid, and of the envy that the men who remain behind will feel as others return with loot. As one informant said, at first he was hesitant to join, but then he saw that the rest of his age group were joining the raid and so he did not want to remain behind. His friends asked him why he was staying back, why he was letting them go on their own? They encouraged him saying, what if they died, would he be happy sitting under this tree by himself, eating meat on his own, having this land all to himself? This he said prompted him to pick up his weapon and follow them.

(c) . Recruitment

A person who has decided to join will easily travel a day's distance to recruit a close, trusted friend he has previously gone on raids with (figure 3). Most men will join a raid only if one or more of such friends are also joining, and similarly will feel obliged to join if their close friends want them to. Subjects noted that these close associates are a warrior's core companions on the raid—the men with whom he can share bullets, water and food, the men most likely to carry him back home if he is injured, the ones he will be standing next to during the firefight. If there will not be a systematic loot division phase these are the men who will together drive back the animals they got, apportion it among themselves, and support each other if seniors, or those who did not get a share, try to grab their animals.

Figure 3.

Recruitment. (a) Who recruited subject to join the raid (n = 45). (b) Whom subject recruited to join, of the subjects who indicated that they recruited someone specific (n = 19). ‘Public’ denotes raids in which subject learned about the raid through ongoing community discussions and decided to join. (Online version in colour.)

For every man who agrees to join the raid, there are several who refuse, so that the number of men mobilized for any particular raid is far fewer than the number of potential recruits. Men are free to join or say no, and no one has the authority to coerce an unwilling man to join. The ethos is that the desire to join should come from one's own heart. Nonetheless, there is peer pressure to join and men who refuse to join usually offer a justification (figure 4). Grazing and watering the animals require travelling several kilometres each day, patrolling for enemy scouts and thieves and engaging in combat to defend the livestock in case of an attack. Neglecting these herding duties is frowned upon and so men who are not in position to hand off herding responsibilities to a trustworthy friend or relative may legitimately excuse themselves. Men who do not own a weapon often refuse, although some young boys join as helpers, carrying water and food for the fighters, and in driving the animals back. Some will sit out a raid because they recently joined another raid. Some stay back to defend the settlement and herds while the rest are gone. Over the course of several raids, chances are that most individuals have joined at least one or a handful of raids. In the areas where raiding is prevalent, even an unwilling man will go on at least one raid, so that he can deflect the taunts of young women and age-mates calling him ‘ekuriana’ (coward) or ‘ekaramit’ (useless man).

Figure 4.

Excuses. Reasons given for not joining the raid by potential recruits approached by subject, of the subjects who tried unsuccessfully to recruit someone (n = 16). (Online version in colour.)

(d) . Exclusion

In most force raids, the goal is to have a large number of warriors and consequently any Turkana man can join any large-scale raid being initiated from any Turkana settlement. Even if word was not sent to their settlement specifically, men who happen to hear of the plan may collect a group of men from their local area and show up at the place where the raiding party is assembling. Warriors who were poor fighters, or cowards and deserters in previous raids are usually not excluded or dissuaded from joining. They are warned that they should not repeat the mistakes they made in the past, and are encouraged to join the raid and prove themselves this time. It is more common to exclude men who committed adultery, disobeyed the diviner's instructions in a previous raid or disrupted the planned course of events in previous raids from joining.

(e) . Assembly

Recruits travel by foot typically 1–3 days from where they are to the settlement initiating the raid (figure 5). A week or two may pass waiting for participants to coalesce, depending on how far the messengers have travelled, how many settlements have been contacted and how large of a force is desired and anticipated. Alternately, if the settlement initiating the raid is distant from the destination of the raid, warriors may travel to a settlement that is en route to the destination, and collect men from there. In this scenario, a group of warriors from one settlement proceed to the other, after having sent word along that they are coming there with the intention of going for a raid. The settlement that they arrive at plays the role of host and takes active part in organization. From here, they send word out to a few more settlements, and wait for men from a wider area to join them.

Figure 5.

Recruitment reach. Number of days for subject to travel to where the raiding party was assembling (n = 50). (Online version in colour.)

(f) . Personal preparations

As they await the arrival of more participants, a person who has decided to join the raid will visit friends and relatives who may offer him ammunition and food supplies. Often, a group of men who have decided to join will ask a friend to kill a goat for them so that they can eat some meat prior to leaving, and carry some for the journey. Those who are not participating in the raid may offer an animal, to alleviate the consequences of not joining themselves, and sometimes with the expectation that they will receive a gift if these men end up successful on the raid. Some young men will get the blessings of their parents before they depart. Other young men may need to exercise more discretion. Their parents may object to them abandoning their herding duties or worry that their son is risking his life by joining this raid. Also, families are averse to sending more than one son on a raid. If one son leaves, the other sons are needed back at home for herding. There is also always a chance that the raiding party will suffer a lethal defeat in which scores of Turkana are killed, and so they take precautions against losing multiple sons if this raid turns out to be catastrophic for the Turkana.

(g) . Dance

As recruits begin to arrive from various settlements and territorial sections to the settlement that has initiated the raid, people group themselves under different trees by their age group and territorial section. The gathering warriors will perform a dance specifically associated with raiding called ‘akinyak’ meant to encourage and embolden the combatants. A few men spontaneously rise up together and dance in unison, speaking words that will encourage their fellow combatants. Firing their weapon in the air they mimic the moves of combat in a stylized form, while others are seated watching them. They note their previous feats in combat and challenge others to do the same on this raid. They declare the acts of bravery they may engage in. They enact what they will do during the firefight, while telling the seated men to take note. Once they sit back down in the crowd, another set of men stand up for their turn and continue in the same fashion. Multiple groups may get up together. One group dances for the other, telling them that they will not let the animals escape from their wing. They warn the other group that their cowardice will be noted. Someone from the other group will dance in response, declaring that he will not be a coward, he will be fighting from the front, he will kill any enemy on his side. Yet another set of men may stand up enacting their role as the middle wing, preventing the enemy's advance from their side. During the dance, men will also pick on particular men who were cowards in previous battles, and taunt them saying that in such and such raid when we went to that place, you ran away, weakening your wing and left others behind to be killed by the enemy. Are you going to fear again? This time, are you going to bring me back home? The coward, when his turn comes, will confess to this, and declare that in this raid he will not do the same, that he will prove himself, he will be the first to kill the enemy and the ones taunting will seem like cowards.

(h) . Communal donations and feasts

Large communal and smaller age-group-specific feasts are organized in which a few camels and bulls and several goats are roasted and consumed by the warriors and elders. Young men are sent to collect animals for the feast from potential donors. Men joining the raid may donate, but those who are staying back may face even stronger pressure to. Some will do so willingly; others refuse saying they recently donated or do not have an animal to spare. Donors are perceived to be generous and their standing in the community is improved. For instance, in one raid in which men recognized as cowards were not punished, the informant felt that they escaped punishment because they are rich and generous men who donate animals to the raiding party for the feast. In addition to the larger feast, smaller groups of 10 or 20 men will go around persuading potential donors by performing akinyak appealing that they are travelling far, have nothing to eat on the way, and the diviner has forbade killing wildlife en route. It is not uncommon for warriors to take animals ‘by force’ wherein an unwilling herdsman's animal is slaughtered without his consent. If the raid is successful, donors may be given an animal from the loot. Individual recruits will also visit friends and relatives to request ammunition or other supplies.

(i) . Blessings

The blessings of elders—men belonging to senior age groups that are too old to join raids—are considered to be crucial for the success of the raid. The blessing is embodied by the sprinkling of water. One function of the pre-raid feast is to sacrifice meat for the elders, and if successful the raiding party will keep aside some animals to sacrifice for the elders upon returning. Elders will advise the men of the way they went to fight in the past, remind them of victorious battles of their times, instruct them that they must not withdraw too soon, that they must stay and fight so that the enemy may be overcome. They remind them that this is not a stealth raid where they are undetected and can run away when they get one, two or three cows. They complain of the lack of courage of the present generation, saying that in their time, they went as a large force to raid the settlement or to surround the meadows and wells, standing their ground in combat, facing the enemy eye-to-eye, resisting the enemy until one side overcame the other. That, they say, is the spirit they want to pass on to the younger generation.

(j) . Exhortations

Leaders, older men and prominent warriors give speeches to spur the raiding party to fight and delineate the plan of action and organization of the raiding party. Many speeches attempt to galvanize men by inciting anger towards the enemy and stirring up a desire for revenge for the livestock and lives they have lost. They are reminded that the raiding party needs only men wholeheartedly determined to join, not men with ambivalent feelings. They are goaded to prove that they are brave, that they can look after their family, that they are men. They are asked to fight even until their ammunition is gone. Some men may stand up and respond that this is what they will do, that they will bring milk to their mothers and animals to their fathers. Older men will ask the young warriors what their father and mother should eat, if they fear. They tell them that the enemy comes to take your animals, so why fear to go raid them? They encourage them to bring the animals home, so that the Turkana can go to graze animals instead of having to eat relief food. They are warned that if they fear and return on the way, fight like cowards on the battlefield, run away during the firefight, lag behind others, that they will be caned and made to kill an animal or even shot by a fellow Turkana. Men with such intentions should remain behind. They are reminded to assist other wings that may be failing, give water to others who are thirsty, carry back people who need help, take injured men to safety hidden from the combat scene and escort them back slowly once the enemy combatants have dispersed.

(k) . Diviners

Twenty-one of the 47 raids for which this data was available were initiated by diviners—people gifted with the capacity to foresee events. Diviners gain access to the supernatural world through dreams, and some become well-regarded for forecasting raids, from attacks that the enemy may imminently launch on the Turkana, to opportunities for the Turkana to launch a successful offensive. Diviners typically do not join raids themselves, but through dreams become aware of the enemy's movements, position and livestock abundance, the specific set of rituals that the raiding party must follow to be successful, and who the carriers of these rituals must be. Specific rituals the appointed individuals do may include slaughtering a particular animal with a certain colouring at a particular location en route to their destination, burying the carcass of the animal or hanging the carcass on a tree en route to the raid. Raids organized by diviners often have prohibitions that the entire raiding party need to follow, such as not to kill wildlife, eat wild fruit, fire their weapons or return back en route, and prescriptions such as requiring all warriors to spit towards the left when they pass a particular point. Following these instructions is considered essential for their success, and if individuals violate the rules it is deemed necessary to abort the raid and return home. If the raiding party proceeds, it does so at its own risk, and catastrophe can ensue. However, raids are seldom aborted if the rituals are not followed. More commonly, when a raid fails, the lack of adherence to the diviner's specifications is brought up as and explanation for what transpired. Alternately, when a raid fails and rituals were followed, diviners are blamed and are accused of having lied to the people. Consequently, diviners who organize raids develop a reputation, and unless accompanied by success, a diviner will eventually sink into oblivion, while other diviners rise in their fame. Although most diviners who initiate raids are men, there are also female diviners who earn recognition. Female diviners tend to organize smaller stealth missions.

(l) . Leaders

Leaders coordinate various activities and are important for making and announcing plans, giving instructions and trying to make the raiding party be of one mind. Most raids will have multiple leaders operating at different levels of influence (figure 6). There may be a leader for the raiding party as a whole—a well-known warrior or the leader of the settlement that initiated the raid. In addition, each age group and settlement has men who are prominent in their respective local areas. As the raiding party assembles, the leaders may meet to discuss detailed plans among themselves. Then the local leaders or age-group leaders return to their respective groups to relay the plans and to keep their group abreast of the ongoing discussions among the elders and leaders. Leadership status is informally attained by virtue of one's qualities and it does not confer coercive authority. Leaders of raids tend to be skilled, courageous, experienced and famed warriors (figure 6). Informants describe them as people who are willing to protect and rescue fellow combatants during a firefight. When the rest of the raiding party is retreating, they stay behind to hold back the enemy, so that the others can escape with the animals. When men fear during the firefight, leaders call them back. When someone is injured, they say he must not be left behind. They guide others on how to fight—the strategy to use, which direction to attack from, how to get access to the loot, and how to drive the animals back. They are good orators who can persuade and motivate people. Not all leaders have all these traits, but a few of these qualities in a person allows him to emerge as a prominent member of his age group or eventually as a settlement or raid leader with a larger scope of influence.

Figure 6.

Leadership. (a) The number of leaders on the raid from the perspective of subject (n = 48). (b) Qualities of leaders (n = 39). (Online version in colour.)

4. Limitations of the study

The data presented here were obtained by conducting interviews with individual warriors about raids they participated in, and not from observational studies of raids or the events leading up to a raid. This methodology allows for the collation of information on raids that transpired over several months to years prior to the study, and across a wider geographical area than observational studies would permit. It is safer and more feasible for the researcher, and prioritizes the viewpoint of the individual warrior as he experienced and remembered the event. However, this methodology can introduce biases in the data for the following reasons: (i) it is subject to cognitive biases in recall which may especially serve to shoehorn events according to cultural ideals; (ii) it is influenced by how individuals desire to portray themselves, and so may be distorted to be favourable to the narrator; (iii) each account is restricted to the knowledge sphere and perceptions of one individual among the hundreds who were involved in the production of the raid; and (iv) individuals' stated motives may not capture the larger socio-political forces that abet the persistence of raiding in this region. In addition, warriors were interviewed in private to reduce the pressure on warriors to render accounts that impress peers or onlookers. However, it is possible that the lack of external witnesses who could corroborate a subject's account may have encouraged accounts that are favourable to the subject.

5. Discussion

The description provided here parallels accounts for how raids were organized in other pastoral groups in East Africa, like the Pokot and Samburu, in several regards. Bollig & Österle [50], writing on Pokot raids, note the importance of blessings by elders, the role of leaders and diviners, the process of building social cohesion through war songs and warrior dances and the inciting of warriors through exhortations. Straight's [54] analysis of war songs among the Samburu suggests that song plays a similar role in Samburu and Turkana martial traditions. Thomas [40] has described the diffuse social pressure exerted on Dodos men to urge them to show up for combat. Glowacki et al. [55] demonstrate how, among the Nyangatom, warriors' social networks are used to recruit participants for raids. The crucial role of age-based groupings for mobilizing for raids has been discussed in several pastoral groups [32,35–37].

The patterns described here suggest that cooperation occurs at multiple scales to mobilize people for large-scale intergroup conflict. At the largest scale, hundreds of participants from multiple settlements and territorial sections convene. It is likely that a warrior would not know a majority of the participants at this scale. Yet, they have coalesced to be instigated by concerns of retaliation, territory and incursions that impact the Turkana widely, spurred by elders to be courageous in battle like their forefathers and bring back livestock so that the Turkana people can eat, instructed about the strategy and plan of attack, warned that they will be caned if they run away and endanger their fellow combatants’ lives or the offense's chances of overcoming the opponent. At the mid scale, age groups gather under their respective trees, feasting and dancing together as they plan how their wing will carry out their attack. Warriors are likely to recognize the majority of their age-group members especially those from their territorial section. They call out and warn known individuals among them who were cowards on previous raids, and acknowledge and praise age-mates who should be emulated. Each age group, especially junior ones, may outline secondary plans nested within the larger plans that aim to protect their interests and ensure they get a fair share of the loot. At the smallest scale are friends, closely bonded men who plan to act like a coalition within the larger raid. They will try their best to stay next to each other, share ammunition, water and food, take steps to transport an injured member of their party home, agree to share the loot among themselves and stand up for each other in case quarrels arise over loot division. Thus, informal mobilization of a large army of voluntary recruits requires building social cohesion at different scales: at the largest scale through shared norms, values and identity; at the mid scale through reputational concerns; and at the coalition scale through reciprocity-based long-term relationships. Mid and coalitional scale interest groups can compromise the success of the overall enterprise, but they seem to be essential building blocks that cultural evolution has harnessed to expand the scale of cooperation.

The various stages and preparations involved in mobilizing a raiding party illustrate that warfare presents not just a cooperative dilemma, but rather a series of cooperative dilemmas. For instance, a man who travelled a day to recruit his close friend to go on the raid may feel disappointed if his friend is unwilling to go, or conversely the friend may feel pressured to join even if he would not otherwise have wanted to. These interactions are embedded within a long-term pairwise relationship of mutual aid and exchange between them. Or consider that a man leaving for a raid needs to find someone trustworthy to take on his most consequential task—caring for his herds including defending them from raids that may be launched against the Turkana. Close kin like father, sons, brothers, uncles and cousins play a key role in assuming these essential duties. As such, kin relationships are uncommon within a raiding party because some close kin stay back to help participants lower the opportunity cost of joining a raid.

Crucially, the close-up view of informal mobilization for Turkana cattle raids highlights that cultural evolution has many potential pathways for acting on social cohesion at different scales, and at different points in the sequence of steps taken when mobilizing for warfare. In the case of Turkana raid mobilization, these have led to the primacy of age-based over lineage-based social structures, of friends over kin, of influential over authoritarian leaders, of voluntary over mandatory participation. In other societies cultural evolution could have taken other paths, making it so that each human society is overcoming the cooperative dilemmas of war in its own unique way. However, the need in informal Turkana raiding to harness a multiplicity of cohesive forces at different scales is strikingly analogous to the characteristics of formal military where a potent mix of motivations, from unit cohesion to national loyalty, are all leveraged to make soldiers risk their lives to fight [26,56–58]. Multi-level cohesion may thus be the common raw material by which different human societies produce war.

The cultural milieu of cattle raiding captured by this data represents a slice of time and space within a larger changing socio-political landscape of cattle raiding in East Africa. Notably, East African cattle raiding traditions over the last few decades have been profoundly affected by the proliferation of firearms, and several authors have noted the lethality, physiological and psycho-social costs, and threats to the stability of pastoralism due to the addition of firearms into historical cattle raiding practices [29,47,48,50,59,60]. Additionally, there is increasing need to interface with state-level institutions to acquire ammunition, which is provided under the justification of defence, and to seek reinforcement from the police and military to pursue raiders from outside Kenya. Nonetheless in the far reaches of northern Turkana where this study was conducted, there is more continuity in cultural traditions of mobilizing for raids, despite these larger socio-political trends. Similarly, unlike in many parts of East Africa, commercial cattle raiding has not become the dominant form of raiding in the sub-population of Turkana studied here. Participants join raids to acquire animals to (re)build their herds, and accumulate wealth for bride-price. Wealth individuals acquire from raids is being redistributed according to normative specifications, including to fathers, sons, brothers, uncles and close friends. The persistence of these war traditions against the pull of commercial raiding and nation-state institutions might be due to the geopolitical remoteness of this region from the Kenyan state. Being close to the northwest border of Kenya, Turkana communities here are regularly raided by the Toposa from South Sudan, the Dodos from Uganda and the Merille from Ethiopia, all of whom are also armed. The perpetual and acute need to mobilize for collective defence might have favoured the continuation of the traditional cultural practices by which raids are organized.

Ethics

The study protocol was approved by the University of California Los Angeles Institutional Review Board. Since most participants were not literate, consent was given verbally with an approved consent script.

Data accessibility

Data are provided as an Excel file in the electronic supplementary material [61].

Authors' contributions

S.M.: conceptualization, data curation, formal analysis, funding acquisition, writing—original draft, writing—review and editing.

Competing interests

I declare I have no competing interests.

Funding

I acknowledge funding from the National Science Foundation Doctoral Dissertation Improvement Grant, Leakey Foundation Dissertation Grant and International Society of Human Ethology Owen Aldis Award for conducting the fieldwork.