Sunday, April 13, 2014

Pinker's List: A Distorted Record of Prehistoric War?

In his Nobel Peace Prize Acceptance Speech in 2009, President Barack Obama had to justify the awarding of the Nobel Peace Prize to a Commander in Chief who was leading his country in two major wars.  He argued that war is so deeply rooted in human nature and the human condition that it can never be completely abolished.  He declared: "War, in one form or another, appeared with the first man."  And yet, explaining how we can and should strive for peace, he quoted from President John Kennedy: "Let us focus on a more practical, more attainable peace, based not on a sudden revolution in human nature but on a gradual evolution in human institutions."  He then repeated that last phrase--"a gradual evolution of human institutions"--as the theme for his speech.  Without trying to change human nature, we can promote peace through institutional evolution--through culturally evolved norms of just war, human rights, global commerce, and international sanctions for punishing unjustified violence.  Obama thus summarized the argument of Steven Pinker that while war and violence express the "inner demons of our nature," we can move towards a life of peaceful coexistence as long as our cultural environment strengthens the "better angels of our nature."

Some of the critics of Pinker's argument think this is deeply mistaken because of its false claim that war has roots in human nature.  For example, in his book chapter--"Pinker's List: Exaggerating Prehistoric War Mortality"--R. Brian Ferguson challenges Pinker's evidence for prehistoric war that would support Obama's claim that "war, in one form or another, appeared with the first man."  (Ferguson's chapter appears in War, Peace, and Human Nature: The Convergence of Evolutionary and Cultural Views, edited by Douglas Fry [Oxford University Press, 2013].  A copy is available online.)

Ferguson concentrates his attention on Pinker's Figure 2-2 (page 49), which presents a list of societies showing the percentage of deaths in warfare in nonstate and state societies, classified into four groups: prehistoric archaeological sites, hunter-gatherers, hunter-horticulturalists and other tribal groups, and states.  The bar graphs show that the percentage of deaths in war is much higher for the first three groups than it is for states (ranging from ancient Mexico before 1500 CE to modern states from the 17th century to the present).

Ferguson claims that if one looks at the original sources for this data cited by Pinker, one discovers that Pinker's visual graph distorts the data to make it appear more supportive of his argument than it really is.  First, one should notice that among the 21 groups of prehistoric gravesites, the oldest archaeological site (Gobero, Niger, 14,000-6,200 BCE) has no war deaths at all.  And a couple of the prehistoric sites (Sarai Nahar Rai, India, 2140-850 BCE, and Nubia, 12,000-10,000 BCE) have only one violent death each.  If three skeletons are found at a site, and one of them shows evidence of violent death, then Pinker presents this as a bar graph showing 33% of deaths in war, which is much higher than that for modern states.  Surely, Ferguson suggests, one violent death at one gravesite hardly shows extensive warfare, but Pinker does not explain this to his reader.  Moreover, Ferguson notes, one set of 30 sites is from British Columbia, 3,500 BCE to 1674 CE.  Although he concedes this evidence for warfare, Ferguson indicates that these Indians along the Pacific Northwest Coast were "complex" hunter-gatherers--that is, hunter-gatherers who had settled into large villages with some hierarchical social structures, which was not characteristic of the nomadic hunter-gatherers who were our original ancestors.

Pinker presents bar graphs showing a range of 5% to 60% deaths in warfare for 8 hunter-gatherer societies.  But Ferguson points out that Pinker does not tell his reader that for two of these societies (the Ache of Paraguay and the Hiwi of Venezuela-Columbia), all of the war deaths were indigenous people killed by frontiersmen.

Pinker's bar graphs for 10 societies of hunter-horticulturalists and other tribal groups show a range of 15% to 60% deaths in warfare.  The 60% rate of death in war is the highest rate ever recorded by anthropologists, and it's for the Waorani of Eastern Ecuador.  When I was travelling through the Ecuadorian rainforest last summer, I heard about the Waorani and their reputation for violence.  One of my Quichua guides identified them as auca--"savages."

Ferguson concedes that the archaeological and anthropological evidence shows intense warfare among many complex hunter-gatherers and horticulturalists, but he argues that nomadic hunter-gatherers would not have shown this.  When one sees evidence of one or a few violent deaths among a group of nomadic hunter-gatherers, this should be identified as homicide not war.

Like Douglas Fry, Ferguson agrees that there has been lethal violence among nomadic hunter-gatherers, but this was personal violence rather than war.

In defense of Pinker, one could argue for Richard Wrangham's distinction between "simple" and "complex" war.  Like chimpanzees, nomadic hunter-gatherers do not fight pitched battles under the formal command of military leaders, because such "complex" warfare arises only in agrarian societies with military and political hierarchies.  Nomadic hunter-gatherers will kill members of outside groups only when the killers can surprise their outnumbered victims and then retreat after killing only a few individuals.  This raiding and feuding will not result in large numbers of battle deaths, and thus the archaeological record will not show any evidence of large numbers of violent deaths among nomadic hunter-gatherers.  Moreover, Pinker and Wrangham would predict that violent raiding and feuding among hunter-gatherers is infrequent, with long periods of peace, although the rate of killing is still comparable to that of American cities today.

Ferguson concludes: "We are not hard-wired for war.  We learn it" (126).

He does not indicate that those like Pinker and Wrangham actually agree with him about this.  They agree that war is not a biological necessity, although there are biological propensities to violence that can be triggered by the social environment.  They also agree with Ferguson that the establishment of agrarian societies with bureaucratic states created "complex" warfare as a purely cultural invention.  They also agree that the cultural evolution of recent centuries can move us towards peace.

Pinker and Wrangham agree with Obama and Kennedy:  in the quest for peace, we need not a sudden revolution in human nature but a gradual evolution in human institutions.

Some of these points are developed in earlier posts here, here, here., here, and here.

Brian Ferguson has pointed out to me that I have made a mistake here in attributing to him the point about the Hiwi and the Ache, because Ferguson only deals with the archaeological data in Pinker's list.  Actually, the point about the Hiwi and Ache was made by Douglas Fry (17-18).

1 comment:

Troy Camplin said...

I love it when people say, "Humans are not hard-wired for X, we learned it." They never go on to explain how we could have learned it. If humans did not ever engage in war, how on earth could we have learned how to engage in war? Did someone just think it up one day? That, of course, is what they think -- demonstrating they are, at heart, creationists.