The Origins of War:The Origins of War:The Evolution of Intergroup Violence in The Evolution of Intergroup Violence in

Animals and ManAnimals and Man

Based on: Based on: The Origin of War:The Origin of War:The Evolution of a Male-Coalitional

Reproductive Strategy

Johan M.G. van der Dennen

The Origins of War• What this presentation is not about:

The Origins of War• What this presentation is not about:

– Hypertrophy of aggression

The Origins of War• What this presentation is not about:

– Hypertropy of aggression– Aggression instincts

The Origins of War• What this presentation is not about:

– Hypertrophy of aggression– Aggression instincts– ‘Todestrieb’ or other destructive inclinations

The Origins of War• What this presentation is not about:

– Hypertrophy of aggression– Aggression instincts– ‘Todestrieb’ or other destructive inclinations– Innate belligerence or bellicosity

The Origins of War• What this presentation is not about:

– Hypertrophy of aggression– Aggression instincts– ‘Todestrieb’ or other destructive inclinations– Innate belligerence or bellicosity– ‘Evil’ or malicious/malevolent Man(kind)

The Origins of War• What this presentation is not about:

– Hypertrophy of aggression– Aggression instincts– ‘Todestrieb’ or other destructive inclinations– Innate belligerence or bellicosity– ‘Evil’ or malicious/malevolent Man(kind)

• These are only quasi-explanations of human behavior

The Origins of War• War as a unique one-time cultural invention

The Origins of War• War as a unique one-time cultural invention

The Origins of War• War as a unique one-time cultural invention

This picture from Australia’s ‘Kakadu National Park’ is at least ten thousand years old.

The Origins of War• War as a unique one-time cultural invention

This picture from Australia’s ‘Kakadu National Park’ is at least ten thousand years old.

But are these hunters or warriors?

The Origins of War• War as a unique one-time cultural invention

This picture from Australia’s ‘Kakadu National Park’ is at least ten thousand years old.

But are these hunters or warriors? Does a

hunter need a shield?

The Origins of War• or phylogenetic (evolutionary) continuity?

The Origins of War• or phylogenetic (evolutionary) continuity?

From altercations and skirmishes between animal territorial groups

The Origins of War• or phylogenetic (evolutionary) continuity?

Via violent conflicts between preindustrial (nonstate) societies

The Origins of War• or phylogenetic (evolutionary) continuity?

Until ‘real’ wars between city-states, states, and empires

The Origins of War• or phylogenetic (evolutionary) continuity?

Until ‘real’ wars between city-states, states, and empires

From altercations and skirmishes between animal territorial groups

Via violent conflicts between preindustrial (nonstate) societies

The Origins of War• Three central problems:

The Origins of War • Three central problems:

– Why war in only so few organisms?

The Origins of War• Three central problems:

– Why war in only so few organisms?– Why this absence of intergroup competition?

The Origins of War• Three central problems:

– Why war in only so few organisms?– Why this absence of intergroup competition?– Why only males as warriors or soldiers?

The Origins of War• Three central problems:

– Why war in only so few organisms?– Why this absence of intergroup competition?– Why only males as warriors or soldiers?

• Plus two proximate-level questions:

The Origins of War• Three central problems:

– Why war in only so few organisms?– Why this absence of intergroup competition?– Why only males as warriors or soldiers?

• Plus two proximate-level questions:

• War causation (Why are particular wars waged?)

The Origins of War• Three central problems:

– Why war in only so few organisms?– Why this absence of intergroup competition?– Why only males as warriors or soldiers?

• Plus two proximate-level questions:

• War causation (Why are particular wars waged?)

• Combat motivation (Why do males fight?)

The Origins of War• The principal thesis of my evolutionary

scenario (evolutionario): War originated as the result of enhanced (polyadic, coalitional) cooperation between (a number of) males within groups for the purpose of violent competition between groups for females and territory (or territory and the females – and other resources – on it).

The Origins of War• Alternatively, Wrangham (1999) presents

his adaptive hypothesis for explaining the species distribution of intergroup coalitional killing. This is the Imbalance-of-Power Hypothesis, which suggests that coalitional killing is the expression of a drive for dominance over neighbors.

The Origins of War• Two conditions are proposed to be both

necessary and sufficient to account for coalitional killing of neighbors: (1) a state of intergroup hostility; (2) sufficient imbalances of power between parties that one party can attack the other with impunity. Under these conditions, it is suggested, selection favors the tendency to hunt and kill rivals when the costs are sufficiently low.

The Origins of War• But whether for territory/females or

intergroup dominance (which do not exclude each other anyway), warring behavior may be considered to be a strategy which, as all other behaviors, originated and developed in the course of evolution for the optimation of reproductive success.

The Origins of War

The Origins of War• Even if it looks like males (individual or in

coalitions) are fighting only for dominance or territorial expansion, the underlying rationale is the lifelong attempt to enhance their chances of reproductive success through monopolization of one or more females, or increased access to females (via subtle, sneaky, or aggressive/violent tactics).

The Origins of War• In social carnivores and primates it is the

females who form the stable social group-territorial core. They live in family groups of related females and their offspring. They benefit most from the integrity or expansion of the group territory; they have the most to lose. But because their aim is ‘only’ the strategic retreat of the other group – and not reproductive success – their willingness to incur injuries or even death is very slight.

The Origins of War• Two principal modes or forms of intergroup

antagonism:

The Origins of War• Two principal modes or forms of intergroup

antagonism:

• The (pitched) battle or combat (in humans often ritualized to a large extent)

The Origins of War

These are some examples of battle or combat in humans. Above: The Dani (New Guinea).

Below: the phalanx – the greatest invention in the history of ‘civilized’ warfare.

The Origins of War• Two principal modes or forms of intergroup

antagonism :• The (pitched) battle or combat (in humans

often ritualized to a large extent)• The raid or ambush (lethal male raiding)

(only to be found in humans [universally] and chimpanzees [at least in some populations] – and much more lethal than the battles through small but rapidly accumulating casualties)

Example of lethal male raiding by Timucua (Florida) Indians (de Bry, ± 1590). This is the archetypical raid; note the incendiary arrows.

The Origins of War

Intergroup antagonism in female macaques (Macaca mulatta). Please observe the two combat lines (battle arrays).

The Origins of War

The Origins of War• In only two known species (Homo sapiens

and Pan troglodytes) it is the males who use coalitional violence – but then cold-blooded and level-headed. Male chimps go ‘on patrol’ to penetrate into the territory of ‘the enemy’ and attack numerically weaker foraging parties – and severely maul and mortally injure their hapless victims. Their behavior looks very deliberate, purposeful and intentional - like a guerrilla operation.

The Origins of War

Two Kasakela males inspect the territory of ‘the enemy’. Observe the contrast with the excited and vociferous

behavior of the macaque females.

The Origins of War

Here is another example of chimpanzee males going ‘on patrol’ intentionally and apparently in cold-blood. They look startled and alert rather than aggressive or angry.

The Origins of War• The insufficiently explained phenomenon

of female migration between groups (or male philopatry) in the HUCHIBO (HUmans, CHImps, BOnobos [Pan paniscus]) clade...

The Origins of War• ... is allegedly responsible for the origin and

evolution of a specific male psychology of (polyadic) coalition formation. This ‘coalitional psychology’ probably evolved initially through kin selection. A within-group coalition of cooperating and concertedly operating males is an eminent and superb instrument in the competition between groups for resources. For the reproductive success of males females are the ‘ultimate’ limiting resource.

The Origins of War• Necessary conditions for the origin and

evolution of war in the protohistory of the human species have been:

The Origins of War• Necessary conditions for the origin and

evolution of war in the protohistory of the human species have been:– the ability to cooperate and form coalitions

The Origins of War• Necessary conditions for the origin and

evolution of war in the protohistory of the human species have been:– the ability to cooperate and form coalitions

• Kin selection (inclusive fitness, nepotism) (Hamilton)

• Reciprocal altruism (reciprocity) (Trivers)

• The ‘risk-contract’ theory of coalitions (Tooby & Cosmides)

The Origins of War• Necessary conditions for the origin and

evolution of war in the protohistory of the human species have been:– the ability to cooperate and form coalitions – a certain amount of ethnocentrism

The Origins of War• Necessary conditions for the origin and

evolution of war in the protohistory of the human species have been:– the ability to cooperate and form coalitions – a certain amount of ethnocentrism– a high degree of social intelligence

The Origins of War• Necessary conditions for the origin and

evolution of war in the protohistory of the human species have been:– the ability to cooperate and form coalitions – a certain amount of ethnocentrism– a high degree of social intelligence

• ‘theory of mind’; Machiavellian intelligence (suggesting malicious manipulation) or, more neutrally, ‘strategic’ intelligence

The Origins of War• Necessary conditions for the origin and

evolution of war in the protohistory of the human species have been:– the ability to cooperate and form coalitions – a certain amount of ethnocentrism– a high degree of social intelligence– ecological dominance

The Origins of War• Necessary conditions for the origin and

evolution of war in the protohistory of the human species have been:– the ability to cooperate and form coalitions – a certain amount of ethnocentrism– a high degree of social intelligence– ecological dominance

• putting a selection premium on larger groups, on an arms race toward even more social intelligence and communication, on technological intelligence (weapon technology), and on hypersociality (synergisms: Corning)

The Origins of War• Misunderstandings about war

• An evolutionary theory of (the origin of) war does not necessarily imply– that war is a universal and ubiquitous

phenomenon (and we are stuck with it)

The Origins of War• Misunderstandings about war

• An evolutionary theory of (the origin of) war does not necessarily imply– that war is a universal and ubiquitous

phenomenon (and we are stuck with it)– that “men like fighting” (as the military

historian Van Creveld does not tire of proclaiming)

The Origins of War• Misunderstandings about war• An evolutionary theory of (the origin of)

war does not necessarily imply– that war is a universal and ubiquitous

phenomenon (and we are stuck with it)– that “men like fighting” (as the military

historian Van Creveld does not tire of proclaiming)

– or that humanity is ‘damned’ to war for all eternity. Even among the most warlike societies peace is the normal condition.

The Origins of War• Finally…• It is probably not superfluous to make clear that

the conditions under which violent intergroup competition originated and evolved are radically distinct from the conditions of our world today. Warring behavior has become ‘unhooked’ from its selective advantages (as Bobbi Low called it)

The Origins of War• Finally…• It is probably not superfluous to make clear that

the conditions under which violent intergroup competition originated and evolved are radically distinct from the conditions of our world today. Warring behavior has become ‘unhooked’ from its selective advantages (as Bobbi Low called it)

• Modern arms technology makes the cost-benefit calculus of war through massive destruction of human lives and resources increasingly unacceptable (though not necessarily apocalyptic)

The Origins of War