Although the mobile forager data support a clear conclusion that this form of social organization is not conducive to war, nonetheless, as Fry and Söderberg (2014) observe, “A conflagration is raging over whether nomadic foragers are peaceful or warlike” (p. 256). This issue is being debated in academia (Bowles, 2009; Endicott, 2014; Fry and Söderberg, 2013a; Guenther, 2014; Lee, 2014; Wrangham & Glowacki, 2012) as well as presented in the popular press (Gat, 2006; Pinker, 2011; Wrangham & Peterson, 1996). Why is the question of forager warlikeness/peacefulness getting this attention? Fry and Söderberg (2014) suggest that “nomadic forager data are seen as crucial or at least relevant to much larger issues: How old is war? Are humans inherently warlike? Is war an evolved human trait? Can war, ironically, be credited with the development of altruism and cooperation?” (p. 256)
In an attempt address such questions using nomadic forager data, Fry and Söderberg (2013a) decided to investigate lethal violence of all types without labeling, on an a priori basis, particular killing events under categories such as war, feud, homicide, or manslaughter. Instead, these authors examined in detail the features of all cases of lethal aggression reported for a sample of 21 mobile forager societies selected via a systematic methodology from the SCCS (Fry & Söderberg 2013a, 2013b, 2014).
The key findings were that for the 21 mobile forager societies, a total of 148 lethal events of various types were reported in the primary source ethnographies that were written as early as the 1600s but in most case in the 19th and 20th centuries (White, 1989). All 148 lethal events were analyzed in the study. The mean number of lethal events per society was 7.05 (SD = 14.64), with a range from zero to 69. At one end of this distribution, three societies had no lethal events reported, whereas at the other extreme, one society, the Tiwi of Australia, provided 69 lethal events of the 148. The distribution was skewed, as reflected by the fact that the next highest society had 15 lethal events and the third highest had 10. In other words, the Tiwi, with almost half (47 percent) of the lethal events for the entire sample, was an outlier. If the Tiwi data are removed, the mean number of lethal events per society for the remaining 20 societies is nearly cut in half, with the new mean being 3.95, down from 7.05.
If we think of warfare as lethal aggression between different communities, then the Fry and Söderberg (2013a) findings contradict in various ways the presumption that war is typical of nomadic foraging societies. First, 55 percent of the lethal events involved only one person killing only one person. This does not accord with typical definitions of war as intergroup aggression. Another 23 percent of the lethal instances involved more than one person killing only one person. In other words, 78 percent of the lethal acts involved only one victim. Second, at the very least, 36 percent of the killers and victims were living within the same group as neighbors, fathers and sons, husbands and wives, and so forth. Killing within the same group is not war. Third, an examination of the motivations for lethal aggression revealed that interpersonal reasons were more typical than intergroup causes, whether or not killers and victims were from the same or different groups. Interpersonal jealousy, insults, and revenge were common reasons for killings. However, in a typical lethal scenario wherein a wife leaves her husband for another man and then someone in the love triangle ends up dead, this is not warfare. Similarly, the occasional cases of starvation cannibalism, hunting accidents, or within-group executions do not qualify as examples of warfare. Overall, Fry and Söderberg (2013a) conclude that most lethal aggression cases among the mobile forager societies in the SCCS-derived sample are homicides, a few others are feud, and only a minority could be considered war.