Is war in our genes?

Contemporary Global Politics

War in Human Nature?

The 1971 Tanzanian war

The 1971 Tanzanian war The Gombe war

Chimpanzee conflict
recorded by Jane Goodall

Chimpanzees fighting

Is war a human specificity?

Standard view until 1960s: intraspecies killings are specific to humans
But much evidence to the contrary
- Chimpanzees
- Lions
At the same time, other species can also cooperate
- Trees
- Sea rocket
- Ground squirrels

Notes

We used to think so up to the 1960s. Yet there is large evidence that animals are no more peaceful than we are.

In particular, we used to think that intra-species killing were rare, but they are in fact one of the main causes of mortality.
- Chimpanzees are highly territorial:
  - Males patrol the boundaries of the group's territory and attack intruders
  - Raid foreign territories.
- Infants very vulnerable
  - New leader of a lion pride kills the cubs of the previous leader.
  - Siblings often kill/canibalize each other, esp. when food is short.
- Intraspecific killing among humans \(\leq\) other animal species.
  - According to some, it is many times inferior to that of any mammalian species studied
- Overall, humans are not an exception in killing their kind.
Yet, not all species are equally violent
- Common chimpanzee is violent
- Pigmy chimpanzee or bonobos less so
Are humans closer to the Bonobos?

Is war a human specificity?

Humans in the state of nature

Hobbes
Rousseau

How do we know?

Humans in the state of nature: Three sources of information

Study of animal aggression and fighting
Hunter-gatherers
- surviving ones
- prehistoric evidence
Evolutionary theory

Did hunter-gatherers fight?

The problem of evidence
Contamination problems
Today’s hunter-gatherers are different: isolated, poor environments
Evidence from the Pleistocene is inconclusive
Best: Australian Lab

Did hunter-gatherers fight?

The myth of the peaceful savage
1960s: peaceful aborigines, e.g. Arctic Eskimos But:
- harsh environment -> thinly spread
- Diffuse resources, hard to monopolise
- High level of violence
- 90% of hunter-gatherer societies have intergroup warfare at least every 2 years

Notes

The surviving hunter-gatherer groups have survived perhaps for a reason. I.e., they are not representative of the prehistorical hunter-gatherers.
- Largely confined to poor environments (Arctic, deserts) unsuitable for agriculture
- Low population densities
- Move a lot to subsist
- Few possessions
Poster case was the central Canadian Arctic Eskimos
- Not surprising given harsh environment and thinly spread. Resources very diffuse and hard to monopolize
- Even then, they had a very high rate of quarrels, blood feuds, and homicide (often to kidnap women). 10 times higher than USA at their peak of 1990
- Other Eskimos living in different conditions (e.g., Greenland and coastal Alaska) were strongly territorial and war-like.
Another poster case: the Kalahari Bushmen, east African Hadza, and central African Pygmies, celebrated as peaceful.
- Yet clear evidence that there was fighting not only with their agricultural neighbors, but also among themselves even before contact with non-hunter–gatherers.
- Homicide rates very high, far higher than US or any other state society
- Much of that fighting centered on the water-holes vital for survival in this area,
- Only with enforcement of law by Canada and southern Africa did violence rates decrease.
A comparative study of 99 hunter-gatherer groups, belonging to 37 different cultures, found that nearly all engaged in warfare. Most engaged in intergroup warfare at least every two years (on par with other human societies)

The decline of war (?)

Three major steps in the decline of violence

Rise of the state-leviathan
1815–1945
1945–

Hobbes was right

Percentage of deaths in warfare in nonstate and state societies (Pinker, p. 49)

Notes

Rise of states \(\rightarrow\) mortality drops from 15% of pop (25% of men) to about 1–5%. Why? enforcement of internal peace by the leviathan
Notes on graph, from Pinker:
- ``The topmost cluster shows the rate of violent death for skeletons dug out of archaeological sites. They are the remains of hunter-gatherers and hunter-horticulturalists from Asia, Africa, Europe, and the Americas and date from 14,000 BCE to 1770 CE, in every case well before the emergence of state societies or the first sustained contact with them. The death rates range from 0 to 60 percent, with an average of 15 percent average of the rates of death by warfare is within a whisker of the average estimated from the bones: 14 percent, with a range from 4 percent to 30 percent.
- In the next cluster I’ve lumped pre-state societies that engage in some mixture of hunting, gathering, and horticulture. All are from New Guinea or the Amazon rain forest, except Europe’s last tribal society, the Montenegrins, whose rate of violent death is close to the average for the group as a whole, 24.5 percent
- Finally we get to some figures for states. The earliest are from the cities and empires of pre-Columbian Mexico, in which 5 percent of the dead were killed by other people. That was undoubtedly a dangerous place, but it was a third to a fifth as violent as an average pre-state society. When it comes to modern states, we are faced with hundreds of political units, dozens of centuries, and many subcategories of violence to choose from (wars, homicides, genocides, and so on), so there is no single “correct” estimate. But we can make the comparison as fair as possible by choosing the most violent countries and centuries, together with some estimates of violence in the world today. As we shall see in chapter 5, the two most violent centuries in the past half millennium of European history were the 17th, with its bloody Wars of Religion, and the 20th, with its two world wars. The historian Quincy Wright has estimated the rate of death in the wars of the 17th century at 2 percent, and the rate of death in war for the first half of the 20th at 3 percent. If one were to include the last four decades of the 20th century, the percentage would be even lower. ''

But the 20th century was the bloodiest, right?

Yes, in terms of absolute casualties.
But not in terms of % of population killed

But the 20th century was the bloodiest, right?

Source: Pinker p. 197

But is war-deaths per capita the right metric?

Maybe fewer people exposed to risk of death (i.e., not less war-prone)
Death may decrease because medicine improves
Population growth is exponential
Leaders never know ex ante how many deaths

Better measure of war-proneness: of Arsonists and Trees

Deaths per capita may be the wrong measure of war-proneness

So, has the NUMBER of wars decreased?

The long peace (1945–)

What is the long peace?

0 nuclear weapons used
0 tactical nuclear weapons used
0 war between great powers
0 interstate wars in Europe
0 interstate wars between major developed countries
0 forced territory expansion by developed countries (exception: Israel)
0 states have disappeared through conquest

Why the long peace?

Territorial integrity norm
Democratization
Decline of role of state to preserve honor
Commerce
The bomb?

War in Human Nature?

The 1971 Tanzanian war

The 1971 Tanzanian war The Gombe war

Is war a human specificity?

Is war a human specificity?

Is war a human specificity?

Humans in the state of nature

Humans in the state of nature: Three sources of information

Did hunter-gatherers fight?

Did hunter-gatherers fight?

The decline of war (?)

Three major steps in the decline of violence

Hobbes was right

But the 20th century was the bloodiest, right?

But the 20th century was the bloodiest, right?

But is war-deaths per capita the right metric?

Better measure of war-proneness: of Arsonists and Trees

So, has the NUMBER of wars decreased?

So, has the NUMBER of wars decreased?

So, has the NUMBER of wars decreased?

So, has the NUMBER of wars decreased?

The long peace (1945–)

What is the long peace?

Why the long peace?

Is the long peace really surprising?