sponsored links
TED2007

Steven Pinker: The surprising decline in violence

March 3, 2007

Steven Pinker charts the decline of violence from Biblical times to the present, and argues that, though it may seem illogical and even obscene, given Iraq and Darfur, we are living in the most peaceful time in our species' existence.

Steven Pinker - Psychologist
Steven Pinker questions the very nature of our thoughts -- the way we use words, how we learn, and how we relate to others. In his best-selling books, he has brought sophisticated language analysis to bear on topics of wide general interest. Full bio

sponsored links
Double-click the English subtitles below to play the video.
Images like this, from the Auschwitz concentration camp,
00:25
have been seared into our consciousness during the twentieth century
00:29
and have given us a new understanding of who we are,
00:34
where we've come from and the times we live in.
00:39
During the twentieth century, we witnessed the atrocities
00:42
of Stalin, Hitler, Mao, Pol Pot, Rwanda and other genocides,
00:46
and even though the twenty-first century is only seven years old,
00:51
we have already witnessed an ongoing genocide in Darfur
00:55
and the daily horrors of Iraq.
00:59
This has led to a common understanding of our situation,
01:02
namely that modernity has brought us terrible violence, and perhaps
01:05
that native peoples lived in a state of harmony that we have departed from, to our peril.
01:09
Here is an example
01:12
from an op-ed on Thanksgiving, in the Boston Globe
01:17
a couple of years ago, where the writer wrote, "The Indian life
01:20
was a difficult one, but there were no employment problems,
01:24
community harmony was strong, substance abuse unknown,
01:27
crime nearly non-existent, what warfare there was between tribes
01:30
was largely ritualistic and seldom resulted in indiscriminate
01:34
or wholesale slaughter." Now, you're all familiar with this treacle.
01:37
We teach it to our children. We hear it on television
01:42
and in storybooks. Now, the original title of this session
01:45
was, "Everything You Know Is Wrong," and I'm going to present evidence
01:50
that this particular part of our common understanding is wrong,
01:53
that, in fact, our ancestors were far more violent than we are,
01:56
that violence has been in decline for long stretches of time,
02:00
and that today we are probably living in the most peaceful time in our species' existence.
02:04
Now, in the decade of Darfur and Iraq,
02:07
a statement like that might seem somewhere between hallucinatory
02:12
and obscene. But I'm going to try to convince you
02:15
that that is the correct picture. The decline of violence
02:18
is a fractal phenomenon. You can see it over millennia,
02:24
over centuries, over decades and over years,
02:27
although there seems to have been a tipping point at the onset
02:31
of the Age of Reason in the sixteenth century. One sees it
02:33
all over the world, although not homogeneously.
02:37
It's especially evident in the West, beginning with England
02:41
and Holland around the time of the Enlightenment.
02:44
Let me take you on a journey of several powers of 10 --
02:47
from the millennium scale to the year scale --
02:51
to try to persuade you of this. Until 10,000 years ago, all humans
02:53
lived as hunter-gatherers, without permanent settlements
02:57
or government. And this is the state that's commonly thought
03:00
to be one of primordial harmony. But the archaeologist
03:03
Lawrence Keeley, looking at casualty rates
03:09
among contemporary hunter-gatherers, which is our best source
03:13
of evidence about this way of life, has shown a rather different conclusion.
03:17
Here is a graph that he put together
03:23
showing the percentage of male deaths due to warfare
03:25
in a number of foraging, or hunting and gathering societies.
03:28
The red bars correspond to the likelihood that a man will die
03:33
at the hands of another man, as opposed to passing away
03:39
of natural causes, in a variety of foraging societies
03:42
in the New Guinea Highlands and the Amazon Rainforest.
03:46
And they range from a rate of almost a 60 percent chance that a man will die
03:50
at the hands of another man to, in the case of the Gebusi,
03:53
only a 15 percent chance. The tiny, little blue bar in the lower
03:57
left-hand corner plots the corresponding statistic from United States
04:01
and Europe in the twentieth century, and includes all the deaths
04:05
of both World Wars. If the death rate in tribal warfare had prevailed
04:09
during the 20th century, there would have been two billion deaths rather than 100 million.
04:14
Also at the millennium scale, we can look
04:20
at the way of life of early civilizations such as the ones described
04:23
in the Bible. And in this supposed source of our moral values,
04:28
one can read descriptions of what was expected in warfare,
04:33
such as the following from Numbers 31: "And they warred
04:37
against the Midianites as the Lord commanded Moses,
04:40
and they slew all the males. And Moses said unto them,
04:43
'Have you saved all the women alive? Now, therefore, kill every male
04:46
among the little ones and kill every woman that hath known man
04:50
by lying with him, but all the women children that have not know a man
04:53
by lying with him keep alive for yourselves.'" In other words,
04:57
kill the men; kill the children; if you see any virgins,
05:00
then you can keep them alive so that you can rape them.
05:05
You can find four or five passages in the Bible of this ilk.
05:08
Also in the Bible, one sees that the death penalty
05:12
was the accepted punishment for crimes such as homosexuality,
05:15
adultery, blasphemy, idolatry, talking back to your parents --
05:20
(Laughter) -- and picking up sticks on the Sabbath.
05:24
Well, let's click the zoom lens
05:28
down one order of magnitude, and look at the century scale.
05:31
Although we don't have statistics for warfare throughout
05:34
the Middle Ages to modern times,
05:39
we know just from conventional history -- the evidence
05:40
was under our nose all along that there has been a reduction
05:43
in socially sanctioned forms of violence.
05:47
For example, any social history will reveal that mutilation and torture
05:50
were routine forms of criminal punishment. The kind of infraction
05:54
today that would give you a fine, in those days would result in
05:57
your tongue being cut out, your ears being cut off, you being blinded,
06:01
a hand being chopped off and so on.
06:05
There were numerous ingenious forms of sadistic capital punishment:
06:07
burning at the stake, disemboweling, breaking on the wheel,
06:12
being pulled apart by horses and so on.
06:15
The death penalty was a sanction for a long list of non-violent crimes:
06:18
criticizing the king, stealing a loaf of bread. Slavery, of course,
06:22
was the preferred labor-saving device, and cruelty was
06:27
a popular form of entertainment. Perhaps the most vivid example
06:31
was the practice of cat burning, in which a cat was hoisted
06:34
on a stage and lowered in a sling into a fire,
06:37
and the spectators shrieked in laughter as the cat, howling in pain,
06:40
was burned to death.
06:46
What about one-on-one murder? Well, there, there are good statistics,
06:48
because many municipalities recorded the cause of death.
06:51
The criminologist Manuel Eisner
06:57
scoured all of the historical records across Europe
07:02
for homicide rates in any village, hamlet, town, county
07:04
that he could find, and he supplemented them
07:09
with national data, when nations started keeping statistics.
07:11
He plotted on a logarithmic scale, going from 100 deaths
07:15
per 100,000 people per year, which was approximately the rate
07:22
of homicide in the Middle Ages. And the figure plummets down
07:28
to less than one homicide per 100,000 people per year
07:33
in seven or eight European countries. Then, there is a slight uptick
07:38
in the 1960s. The people who said that rock 'n' roll would lead
07:42
to the decline of moral values actually had a grain of truth to that.
07:46
But there was a decline from at least two orders of magnitude
07:50
in homicide from the Middle Ages to the present,
07:54
and the elbow occurred in the early sixteenth century.
07:57
Let's click down now to the decade scale.
08:02
According to non-governmental organizations
08:04
that keep such statistics, since 1945, in Europe and the Americas,
08:07
there has been a steep decline in interstate wars,
08:11
in deadly ethnic riots or pogroms, and in military coups,
08:15
even in South America. Worldwide, there's been a steep decline
08:19
in deaths in interstate wars. The yellow bars here show the number
08:23
of deaths per war per year from 1950 to the present.
08:29
And, as you can see, the death rate goes down from 65,000 deaths
08:34
per conflict per year in the 1950s to less than 2,000 deaths
08:38
per conflict per year in this decade, as horrific as it is.
08:42
Even in the year scale, one can see a decline of violence.
08:46
Since the end of the Cold War, there have been fewer civil wars,
08:50
fewer genocides -- indeed, a 90 percent reduction since post-World War II highs --
08:53
and even a reversal of the 1960s uptick in homicide and violent crime.
08:59
This is from the FBI Uniform Crime Statistics. You can see
09:05
that there is a fairly low rate of violence in the '50s and the '60s,
09:09
then it soared upward for several decades, and began
09:13
a precipitous decline, starting in the 1990s, so that it went back
09:17
to the level that was last enjoyed in 1960.
09:21
President Clinton, if you're here, thank you.
09:25
(Laughter)
09:27
So the question is, why are so many people so wrong
09:29
about something so important? I think there are a number of reasons.
09:32
One of them is we have better reporting. The Associated Press
09:36
is a better chronicler of wars over the surface of the Earth
09:39
than sixteenth-century monks were.
09:43
There's a cognitive illusion. We cognitive psychologists know that the easier it is
09:47
to recall specific instances of something,
09:52
the higher the probability that you assign to it.
09:55
Things that we read about in the paper with gory footage
09:58
burn into memory more than reports of a lot more people dying
10:02
in their beds of old age. There are dynamics in the opinion
10:06
and advocacy markets: no one ever attracted observers, advocates
10:12
and donors by saying
10:17
things just seem to be getting better and better.
10:19
(Laughter)
10:21
There's guilt about our treatment of native peoples
10:22
in modern intellectual life, and an unwillingness to acknowledge
10:25
there could be anything good about Western culture.
10:28
And of course, our change in standards can outpace the change
10:31
in behavior. One of the reasons violence went down
10:36
is that people got sick of the carnage and cruelty in their time.
10:39
That's a process that seems to be continuing,
10:42
but if it outstrips behavior by the standards of the day,
10:45
things always look more barbaric than they would have been
10:49
by historic standards. So today, we get exercised -- and rightly so --
10:52
if a handful of murderers get executed by lethal injection
10:56
in Texas after a 15-year appeal process. We don't consider
11:02
that a couple of hundred years ago, they may have been burned
11:07
at the stake for criticizing the king after a trial
11:10
that lasted 10 minutes, and indeed, that that would have been repeated
11:13
over and over again. Today, we look at capital punishment
11:16
as evidence of how low our behavior can sink,
11:21
rather than how high our standards have risen.
11:24
Well, why has violence declined? No one really knows,
11:28
but I have read four explanations, all of which, I think,
11:31
have some grain of plausibility. The first is, maybe
11:36
Thomas Hobbes got it right. He was the one who said
11:39
that life in a state of nature was "solitary, poor, nasty, brutish
11:42
and short." Not because, he argued,
11:47
humans have some primordial thirst for blood
11:51
or aggressive instinct or territorial imperative,
11:54
but because of the logic of anarchy. In a state of anarchy,
11:58
there's a constant temptation to invade your neighbors preemptively,
12:01
before they invade you. More recently, Thomas Schelling
12:05
gives the analogy of a homeowner who hears a rustling
12:08
in the basement. Being a good American, he has a pistol
12:11
in the nightstand, pulls out his gun, and walks down the stairs.
12:13
And what does he see but a burglar with a gun in his hand.
12:17
Now, each one of them is thinking,
12:20
"I don't really want to kill that guy, but he's about to kill me.
12:21
Maybe I had better shoot him, before he shoots me,
12:25
especially since, even if he doesn't want to kill me,
12:29
he's probably worrying right now that I might kill him
12:31
before he kills me." And so on.
12:34
Hunter-gatherer peoples explicitly go through this train of thought,
12:37
and will often raid their neighbors out of fear of being raided first.
12:42
Now, one way of dealing with this problem is by deterrence.
12:47
You don't strike first, but you have a publicly announced policy
12:50
that you will retaliate savagely if you are invaded.
12:55
The only thing is that it's
12:58
liable to having its bluff called, and therefore can only work
13:00
if it's credible. To make it credible, you must avenge all insults
13:05
and settle all scores, which leads to the cycles of bloody vendetta.
13:10
Life becomes an episode of "The Sopranos." Hobbes' solution,
13:14
the "Leviathan," was that if authority for the legitimate use
13:19
of violence was vested in a single democratic agency -- a leviathan --
13:23
then such a state can reduce the temptation of attack,
13:29
because any kind of aggression will be punished,
13:32
leaving its profitability as zero. That would remove the temptation
13:35
to invade preemptively, out of fear of them attacking you first.
13:40
It removes the need for a hair trigger for retaliation
13:44
to make your deterrent threat credible. And therefore, it would lead
13:48
to a state of peace. Eisner -- the man who plotted the homicide rates
13:51
that you failed to see in the earlier slide --
13:57
argued that the timing of the decline of homicide in Europe
14:00
coincided with the rise of centralized states.
14:04
So that's a bit of a support for the leviathan theory.
14:08
Also supporting it is the fact that we today see eruptions of violence
14:11
in zones of anarchy, in failed states, collapsed empires,
14:15
frontier regions, mafias, street gangs and so on.
14:19
The second explanation is that in many times and places,
14:25
there is a widespread sentiment that life is cheap.
14:28
In earlier times, when suffering and early death were common
14:32
in one's own life, one has fewer compunctions about inflicting them
14:36
on others. And as technology and economic efficiency make life
14:40
longer and more pleasant, one puts a higher value on life in general.
14:44
This was an argument from the political scientist James Payne.
14:48
A third explanation invokes the concept of a nonzero-sum game,
14:52
and was worked out in the book "Nonzero" by the journalist
14:56
Robert Wright. Wright points out that in certain circumstances,
15:00
cooperation or non-violence can benefit both parties
15:04
in an interaction, such as gains in trade when two parties trade
15:07
their surpluses and both come out ahead, or when two parties
15:13
lay down their arms and split the so-called peace dividend
15:17
that results in them not having to fight the whole time.
15:20
Wright argues that technology has increased the number
15:24
of positive-sum games that humans tend to be embroiled in,
15:26
by allowing the trade of goods, services and ideas
15:31
over longer distances and among larger groups of people.
15:34
The result is that other people become more valuable alive than dead,
15:38
and violence declines for selfish reasons. As Wright put it,
15:41
"Among the many reasons that I think that we should not bomb
15:47
the Japanese is that they built my mini-van."
15:49
(Laughter)
15:52
The fourth explanation is captured in the title of a book
15:54
called "The Expanding Circle," by the philosopher Peter Singer,
15:58
who argues that evolution bequeathed humans with a sense
16:02
of empathy, an ability to treat other peoples' interests
16:05
as comparable to one's own. Unfortunately, by default
16:10
we apply it only to a very narrow circle of friends and family.
16:14
People outside that circle are treated as sub-human,
16:18
and can be exploited with impunity. But, over history,
16:21
the circle has expanded. One can see, in historical record,
16:25
it expanding from the village, to the clan, to the tribe,
16:29
to the nation, to other races, to both sexes,
16:33
and, in Singer's own arguments, something that we should extend
16:36
to other sentient species. The question is,
16:38
if this has happened, what has powered that expansion?
16:43
And there are a number of possibilities, such as increasing circles
16:46
of reciprocity in the sense that Robert Wright argues for.
16:49
The logic of the golden rule -- the more you think about and interact
16:54
with other people, the more you realize that it is untenable
16:58
to privilege your interests over theirs,
17:02
at least not if you want them to listen to you. You can't say
17:06
that my interests are special compared to yours,
17:09
anymore than you can say that the particular spot
17:12
that I'm standing on is a unique part of the universe
17:15
because I happen to be standing on it that very minute.
17:18
It may also be powered by cosmopolitanism, by histories,
17:21
and journalism, and memoirs, and realistic fiction, and travel,
17:25
and literacy, which allows you to project yourself into the lives
17:29
of other people that formerly you may have treated as sub-human,
17:33
and also to realize the accidental contingency of your own station
17:37
in life, the sense that "there but for fortune go I."
17:41
Whatever its causes, the decline of violence, I think,
17:46
has profound implications. It should force us to ask not just, why
17:49
is there war? But also, why is there peace? Not just,
17:53
what are we doing wrong? But also, what have we been doing right?
17:58
Because we have been doing something right,
18:02
and it sure would be good to find out what it is.
18:04
Thank you very much.
18:06
(Applause).
18:07
Chris Anderson: I loved that talk. I think a lot of people here in the room would say
18:18
that that expansion of -- that you were talking about,
18:22
that Peter Singer talks about, is also driven by, just by technology,
18:25
by greater visibility of the other, and the sense that the world
18:28
is therefore getting smaller. I mean, is that also a grain of truth?
18:32
Steven Pinker: Very much. It would fit both in Wright's theory,
18:36
that it allows us to enjoy the benefits of cooperation
18:40
over larger and larger circles. But also, I think it helps us
18:44
imagine what it's like to be someone else. I think when you read
18:49
these horrific tortures that were common in the Middle Ages, you think,
18:52
how could they possibly have done it,
18:55
how could they have not have empathized with the person
18:57
that they're disemboweling? But clearly,
19:00
as far as they're concerned, this is just an alien being
19:03
that does not have feelings akin to their own. Anything, I think,
19:06
that makes it easier to imagine trading places
19:09
with someone else means that it increases your moral consideration
19:12
to that other person.
19:15
CA: Well, Steve, I would love every news media owner to hear that talk
19:16
at some point in the next year. I think it's really important. Thank you so much.
19:20
SP: My pleasure.
19:22

sponsored links

Steven Pinker - Psychologist
Steven Pinker questions the very nature of our thoughts -- the way we use words, how we learn, and how we relate to others. In his best-selling books, he has brought sophisticated language analysis to bear on topics of wide general interest.

Why you should listen

Steven Pinker's books have been like bombs tossed into the eternal nature-versus-nurture debate. Pinker asserts that not only are human minds predisposed to certain kinds of learning, such as language, but that from birth our minds -- the patterns in which our brain cells fire -- predispose us each to think and behave differently.

His deep studies of language have led him to insights into the way that humans form thoughts and engage our world. He argues that humans have evolved to share a faculty for language, the same way a spider evolved to spin a web. We aren't born with “blank slates” to be shaped entirely by our parents and environment, he argues in books including The Language Instinct; How the Mind Works; and The Blank Slate: The Modern Denial of Human Nature.

Time magazine named Pinker one of the 100 most influential people in the world in 2004. His book The Stuff of Thought was previewed at TEDGlobal 2005. His 2012 book The Better Angels of Our Nature looks at our notion of violence.

For the BBC, he picks his Desert Island Discs >>

The original video is available on TED.com
sponsored links

If you need translations, you can install "Google Translate" extension into your Chrome Browser.
Furthermore, you can change playback rate by installing "Video Speed Controller" extension.

Data provided by TED.

This website is owned and operated by Tokyo English Network.
The developer's blog is here.