TED2007
Steven Pinker: The surprising decline in violence
Filmed:
Readability: 5
3,009,786 views
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 is a professor of cognitive science (the study of the human mind) who writes about language, mind and human nature. Full bio
Steven Pinker is a professor of cognitive science (the study of the human mind) who writes about language, mind and human nature. Full bio
Double-click the English transcript below to play the video.
00:25
Images like this, from the Auschwitz concentration camp,
0
0
4000
00:29
have been seared into our consciousness during the twentieth century
1
4000
5000
00:34
and have given us a new understanding of who we are,
2
9000
5000
00:39
where we've come from and the times we live in.
3
14000
3000
00:42
During the twentieth century, we witnessed the atrocities
4
17000
4000
00:46
of Stalin, Hitler, Mao, Pol Pot, Rwanda and other genocides,
5
21000
5000
00:51
and even though the twenty-first century is only seven years old,
6
26000
4000
00:55
we have already witnessed an ongoing genocide in Darfur
7
30000
4000
00:59
and the daily horrors of Iraq.
8
34000
2000
01:02
This has led to a common understanding of our situation,
9
37000
3000
01:05
namely that modernity has brought us terrible violence, and perhaps
10
40000
4000
01:09
that native peoples lived in a state of harmony that we have departed from, to our peril.
11
44000
3000
01:12
Here is an example
12
47000
5000
01:17
from an op-ed on Thanksgiving, in the Boston Globe
13
52000
3000
01:20
a couple of years ago, where the writer wrote, "The Indian life
14
55000
3000
01:24
was a difficult one, but there were no employment problems,
15
59000
3000
01:27
community harmony was strong, substance abuse unknown,
16
62000
2000
01:30
crime nearly non-existent, what warfare there was between tribes
17
65000
3000
01:34
was largely ritualistic and seldom resulted in indiscriminate
18
69000
3000
01:37
or wholesale slaughter." Now, you're all familiar with this treacle.
19
72000
4000
01:42
We teach it to our children. We hear it on television
20
77000
3000
01:45
and in storybooks. Now, the original title of this session
21
80000
5000
01:50
was, "Everything You Know Is Wrong," and I'm going to present evidence
22
85000
3000
01:53
that this particular part of our common understanding is wrong,
23
88000
3000
01:56
that, in fact, our ancestors were far more violent than we are,
24
91000
4000
02:00
that violence has been in decline for long stretches of time,
25
95000
3000
02:04
and that today we are probably living in the most peaceful time in our species' existence.
26
99000
3000
02:07
Now, in the decade of Darfur and Iraq,
27
102000
4000
02:12
a statement like that might seem somewhere between hallucinatory
28
107000
3000
02:15
and obscene. But I'm going to try to convince you
29
110000
3000
02:18
that that is the correct picture. The decline of violence
30
113000
6000
02:24
is a fractal phenomenon. You can see it over millennia,
31
119000
3000
02:27
over centuries, over decades and over years,
32
122000
3000
02:31
although there seems to have been a tipping point at the onset
33
126000
2000
02:33
of the Age of Reason in the sixteenth century. One sees it
34
128000
4000
02:37
all over the world, although not homogeneously.
35
132000
3000
02:41
It's especially evident in the West, beginning with England
36
136000
2000
02:44
and Holland around the time of the Enlightenment.
37
139000
2000
02:47
Let me take you on a journey of several powers of 10 --
38
142000
3000
02:51
from the millennium scale to the year scale --
39
146000
2000
02:53
to try to persuade you of this. Until 10,000 years ago, all humans
40
148000
4000
02:57
lived as hunter-gatherers, without permanent settlements
41
152000
3000
03:00
or government. And this is the state that's commonly thought
42
155000
3000
03:03
to be one of primordial harmony. But the archaeologist
43
158000
5000
03:09
Lawrence Keeley, looking at casualty rates
44
164000
4000
03:13
among contemporary hunter-gatherers, which is our best source
45
168000
3000
03:17
of evidence about this way of life, has shown a rather different conclusion.
46
172000
6000
03:23
Here is a graph that he put together
47
178000
2000
03:25
showing the percentage of male deaths due to warfare
48
180000
3000
03:28
in a number of foraging, or hunting and gathering societies.
49
183000
4000
03:33
The red bars correspond to the likelihood that a man will die
50
188000
6000
03:39
at the hands of another man, as opposed to passing away
51
194000
3000
03:42
of natural causes, in a variety of foraging societies
52
197000
4000
03:46
in the New Guinea Highlands and the Amazon Rainforest.
53
201000
3000
03:50
And they range from a rate of almost a 60 percent chance that a man will die
54
205000
3000
03:53
at the hands of another man to, in the case of the Gebusi,
55
208000
3000
03:57
only a 15 percent chance. The tiny, little blue bar in the lower
56
212000
4000
04:01
left-hand corner plots the corresponding statistic from United States
57
216000
3000
04:05
and Europe in the twentieth century, and includes all the deaths
58
220000
4000
04:09
of both World Wars. If the death rate in tribal warfare had prevailed
59
224000
5000
04:14
during the 20th century, there would have been two billion deaths rather than 100 million.
60
229000
6000
04:20
Also at the millennium scale, we can look
61
235000
3000
04:23
at the way of life of early civilizations such as the ones described
62
238000
5000
04:28
in the Bible. And in this supposed source of our moral values,
63
243000
5000
04:33
one can read descriptions of what was expected in warfare,
64
248000
4000
04:37
such as the following from Numbers 31: "And they warred
65
252000
3000
04:40
against the Midianites as the Lord commanded Moses,
66
255000
3000
04:43
and they slew all the males. And Moses said unto them,
67
258000
3000
04:46
'Have you saved all the women alive? Now, therefore, kill every male
68
261000
4000
04:50
among the little ones and kill every woman that hath known man
69
265000
3000
04:53
by lying with him, but all the women children that have not know a man
70
268000
4000
04:57
by lying with him keep alive for yourselves.'" In other words,
71
272000
3000
05:00
kill the men; kill the children; if you see any virgins,
72
275000
5000
05:05
then you can keep them alive so that you can rape them.
73
280000
2000
05:08
You can find four or five passages in the Bible of this ilk.
74
283000
4000
05:12
Also in the Bible, one sees that the death penalty
75
287000
3000
05:15
was the accepted punishment for crimes such as homosexuality,
76
290000
5000
05:20
adultery, blasphemy, idolatry, talking back to your parents --
77
295000
4000
05:24
(Laughter) -- and picking up sticks on the Sabbath.
78
299000
4000
05:28
Well, let's click the zoom lens
79
303000
3000
05:31
down one order of magnitude, and look at the century scale.
80
306000
3000
05:34
Although we don't have statistics for warfare throughout
81
309000
4000
05:39
the Middle Ages to modern times,
82
314000
1000
05:40
we know just from conventional history -- the evidence
83
315000
3000
05:43
was under our nose all along that there has been a reduction
84
318000
4000
05:47
in socially sanctioned forms of violence.
85
322000
3000
05:50
For example, any social history will reveal that mutilation and torture
86
325000
4000
05:54
were routine forms of criminal punishment. The kind of infraction
87
329000
3000
05:57
today that would give you a fine, in those days would result in
88
332000
4000
06:01
your tongue being cut out, your ears being cut off, you being blinded,
89
336000
4000
06:05
a hand being chopped off and so on.
90
340000
2000
06:07
There were numerous ingenious forms of sadistic capital punishment:
91
342000
4000
06:12
burning at the stake, disemboweling, breaking on the wheel,
92
347000
2000
06:15
being pulled apart by horses and so on.
93
350000
2000
06:18
The death penalty was a sanction for a long list of non-violent crimes:
94
353000
4000
06:22
criticizing the king, stealing a loaf of bread. Slavery, of course,
95
357000
4000
06:27
was the preferred labor-saving device, and cruelty was
96
362000
3000
06:31
a popular form of entertainment. Perhaps the most vivid example
97
366000
3000
06:34
was the practice of cat burning, in which a cat was hoisted
98
369000
3000
06:37
on a stage and lowered in a sling into a fire,
99
372000
3000
06:40
and the spectators shrieked in laughter as the cat, howling in pain,
100
375000
5000
06:46
was burned to death.
101
381000
2000
06:48
What about one-on-one murder? Well, there, there are good statistics,
102
383000
3000
06:51
because many municipalities recorded the cause of death.
103
386000
6000
06:57
The criminologist Manuel Eisner
104
392000
4000
07:02
scoured all of the historical records across Europe
105
397000
2000
07:04
for homicide rates in any village, hamlet, town, county
106
399000
5000
07:09
that he could find, and he supplemented them
107
404000
2000
07:11
with national data, when nations started keeping statistics.
108
406000
3000
07:15
He plotted on a logarithmic scale, going from 100 deaths
109
410000
7000
07:22
per 100,000 people per year, which was approximately the rate
110
417000
6000
07:28
of homicide in the Middle Ages. And the figure plummets down
111
423000
5000
07:33
to less than one homicide per 100,000 people per year
112
428000
4000
07:38
in seven or eight European countries. Then, there is a slight uptick
113
433000
4000
07:42
in the 1960s. The people who said that rock 'n' roll would lead
114
437000
4000
07:46
to the decline of moral values actually had a grain of truth to that.
115
441000
3000
07:50
But there was a decline from at least two orders of magnitude
116
445000
3000
07:54
in homicide from the Middle Ages to the present,
117
449000
2000
07:57
and the elbow occurred in the early sixteenth century.
118
452000
3000
08:02
Let's click down now to the decade scale.
119
457000
2000
08:04
According to non-governmental organizations
120
459000
2000
08:07
that keep such statistics, since 1945, in Europe and the Americas,
121
462000
4000
08:11
there has been a steep decline in interstate wars,
122
466000
3000
08:15
in deadly ethnic riots or pogroms, and in military coups,
123
470000
4000
08:19
even in South America. Worldwide, there's been a steep decline
124
474000
4000
08:23
in deaths in interstate wars. The yellow bars here show the number
125
478000
5000
08:29
of deaths per war per year from 1950 to the present.
126
484000
4000
08:34
And, as you can see, the death rate goes down from 65,000 deaths
127
489000
4000
08:38
per conflict per year in the 1950s to less than 2,000 deaths
128
493000
4000
08:42
per conflict per year in this decade, as horrific as it is.
129
497000
4000
08:46
Even in the year scale, one can see a decline of violence.
130
501000
3000
08:50
Since the end of the Cold War, there have been fewer civil wars,
131
505000
3000
08:53
fewer genocides -- indeed, a 90 percent reduction since post-World War II highs --
132
508000
6000
08:59
and even a reversal of the 1960s uptick in homicide and violent crime.
133
514000
6000
09:05
This is from the FBI Uniform Crime Statistics. You can see
134
520000
4000
09:09
that there is a fairly low rate of violence in the '50s and the '60s,
135
524000
3000
09:13
then it soared upward for several decades, and began
136
528000
4000
09:17
a precipitous decline, starting in the 1990s, so that it went back
137
532000
4000
09:21
to the level that was last enjoyed in 1960.
138
536000
4000
09:25
President Clinton, if you're here, thank you.
139
540000
2000
09:27
(Laughter)
140
542000
2000
09:29
So the question is, why are so many people so wrong
141
544000
3000
09:32
about something so important? I think there are a number of reasons.
142
547000
4000
09:36
One of them is we have better reporting. The Associated Press
143
551000
3000
09:39
is a better chronicler of wars over the surface of the Earth
144
554000
4000
09:43
than sixteenth-century monks were.
145
558000
4000
09:47
There's a cognitive illusion. We cognitive psychologists know that the easier it is
146
562000
5000
09:52
to recall specific instances of something,
147
567000
3000
09:55
the higher the probability that you assign to it.
148
570000
3000
09:58
Things that we read about in the paper with gory footage
149
573000
3000
10:02
burn into memory more than reports of a lot more people dying
150
577000
4000
10:06
in their beds of old age. There are dynamics in the opinion
151
581000
5000
10:12
and advocacy markets: no one ever attracted observers, advocates
152
587000
5000
10:17
and donors by saying
153
592000
1000
10:19
things just seem to be getting better and better.
154
594000
2000
10:21
(Laughter)
155
596000
1000
10:22
There's guilt about our treatment of native peoples
156
597000
2000
10:25
in modern intellectual life, and an unwillingness to acknowledge
157
600000
3000
10:28
there could be anything good about Western culture.
158
603000
2000
10:31
And of course, our change in standards can outpace the change
159
606000
4000
10:36
in behavior. One of the reasons violence went down
160
611000
2000
10:39
is that people got sick of the carnage and cruelty in their time.
161
614000
3000
10:42
That's a process that seems to be continuing,
162
617000
3000
10:45
but if it outstrips behavior by the standards of the day,
163
620000
4000
10:49
things always look more barbaric than they would have been
164
624000
3000
10:52
by historic standards. So today, we get exercised -- and rightly so --
165
627000
4000
10:56
if a handful of murderers get executed by lethal injection
166
631000
6000
11:02
in Texas after a 15-year appeal process. We don't consider
167
637000
4000
11:07
that a couple of hundred years ago, they may have been burned
168
642000
3000
11:10
at the stake for criticizing the king after a trial
169
645000
3000
11:13
that lasted 10 minutes, and indeed, that that would have been repeated
170
648000
3000
11:16
over and over again. Today, we look at capital punishment
171
651000
4000
11:21
as evidence of how low our behavior can sink,
172
656000
3000
11:24
rather than how high our standards have risen.
173
659000
2000
11:28
Well, why has violence declined? No one really knows,
174
663000
3000
11:31
but I have read four explanations, all of which, I think,
175
666000
4000
11:36
have some grain of plausibility. The first is, maybe
176
671000
3000
11:39
Thomas Hobbes got it right. He was the one who said
177
674000
3000
11:42
that life in a state of nature was "solitary, poor, nasty, brutish
178
677000
5000
11:47
and short." Not because, he argued,
179
682000
4000
11:51
humans have some primordial thirst for blood
180
686000
3000
11:54
or aggressive instinct or territorial imperative,
181
689000
3000
11:58
but because of the logic of anarchy. In a state of anarchy,
182
693000
3000
12:01
there's a constant temptation to invade your neighbors preemptively,
183
696000
4000
12:05
before they invade you. More recently, Thomas Schelling
184
700000
3000
12:08
gives the analogy of a homeowner who hears a rustling
185
703000
2000
12:11
in the basement. Being a good American, he has a pistol
186
706000
2000
12:13
in the nightstand, pulls out his gun, and walks down the stairs.
187
708000
3000
12:17
And what does he see but a burglar with a gun in his hand.
188
712000
2000
12:20
Now, each one of them is thinking,
189
715000
1000
12:21
"I don't really want to kill that guy, but he's about to kill me.
190
716000
4000
12:25
Maybe I had better shoot him, before he shoots me,
191
720000
4000
12:29
especially since, even if he doesn't want to kill me,
192
724000
2000
12:31
he's probably worrying right now that I might kill him
193
726000
3000
12:34
before he kills me." And so on.
194
729000
2000
12:37
Hunter-gatherer peoples explicitly go through this train of thought,
195
732000
4000
12:42
and will often raid their neighbors out of fear of being raided first.
196
737000
3000
12:47
Now, one way of dealing with this problem is by deterrence.
197
742000
3000
12:50
You don't strike first, but you have a publicly announced policy
198
745000
5000
12:55
that you will retaliate savagely if you are invaded.
199
750000
3000
12:58
The only thing is that it's
200
753000
2000
13:00
liable to having its bluff called, and therefore can only work
201
755000
4000
13:05
if it's credible. To make it credible, you must avenge all insults
202
760000
4000
13:10
and settle all scores, which leads to the cycles of bloody vendetta.
203
765000
4000
13:14
Life becomes an episode of "The Sopranos." Hobbes' solution,
204
769000
5000
13:19
the "Leviathan," was that if authority for the legitimate use
205
774000
4000
13:23
of violence was vested in a single democratic agency -- a leviathan --
206
778000
5000
13:29
then such a state can reduce the temptation of attack,
207
784000
3000
13:32
because any kind of aggression will be punished,
208
787000
3000
13:35
leaving its profitability as zero. That would remove the temptation
209
790000
5000
13:40
to invade preemptively, out of fear of them attacking you first.
210
795000
4000
13:44
It removes the need for a hair trigger for retaliation
211
799000
4000
13:48
to make your deterrent threat credible. And therefore, it would lead
212
803000
3000
13:51
to a state of peace. Eisner -- the man who plotted the homicide rates
213
806000
6000
13:57
that you failed to see in the earlier slide --
214
812000
2000
14:00
argued that the timing of the decline of homicide in Europe
215
815000
3000
14:04
coincided with the rise of centralized states.
216
819000
4000
14:08
So that's a bit of a support for the leviathan theory.
217
823000
3000
14:11
Also supporting it is the fact that we today see eruptions of violence
218
826000
4000
14:15
in zones of anarchy, in failed states, collapsed empires,
219
830000
4000
14:19
frontier regions, mafias, street gangs and so on.
220
834000
4000
14:25
The second explanation is that in many times and places,
221
840000
3000
14:28
there is a widespread sentiment that life is cheap.
222
843000
3000
14:32
In earlier times, when suffering and early death were common
223
847000
4000
14:36
in one's own life, one has fewer compunctions about inflicting them
224
851000
4000
14:40
on others. And as technology and economic efficiency make life
225
855000
4000
14:44
longer and more pleasant, one puts a higher value on life in general.
226
859000
4000
14:48
This was an argument from the political scientist James Payne.
227
863000
3000
14:52
A third explanation invokes the concept of a nonzero-sum game,
228
867000
4000
14:56
and was worked out in the book "Nonzero" by the journalist
229
871000
4000
15:00
Robert Wright. Wright points out that in certain circumstances,
230
875000
3000
15:04
cooperation or non-violence can benefit both parties
231
879000
3000
15:07
in an interaction, such as gains in trade when two parties trade
232
882000
6000
15:13
their surpluses and both come out ahead, or when two parties
233
888000
4000
15:17
lay down their arms and split the so-called peace dividend
234
892000
3000
15:20
that results in them not having to fight the whole time.
235
895000
3000
15:24
Wright argues that technology has increased the number
236
899000
2000
15:26
of positive-sum games that humans tend to be embroiled in,
237
901000
4000
15:31
by allowing the trade of goods, services and ideas
238
906000
3000
15:34
over longer distances and among larger groups of people.
239
909000
3000
15:38
The result is that other people become more valuable alive than dead,
240
913000
3000
15:41
and violence declines for selfish reasons. As Wright put it,
241
916000
5000
15:47
"Among the many reasons that I think that we should not bomb
242
922000
2000
15:49
the Japanese is that they built my mini-van."
243
924000
3000
15:52
(Laughter)
244
927000
2000
15:54
The fourth explanation is captured in the title of a book
245
929000
4000
15:58
called "The Expanding Circle," by the philosopher Peter Singer,
246
933000
3000
16:02
who argues that evolution bequeathed humans with a sense
247
937000
3000
16:05
of empathy, an ability to treat other peoples' interests
248
940000
5000
16:10
as comparable to one's own. Unfortunately, by default
249
945000
4000
16:14
we apply it only to a very narrow circle of friends and family.
250
949000
4000
16:18
People outside that circle are treated as sub-human,
251
953000
3000
16:21
and can be exploited with impunity. But, over history,
252
956000
4000
16:25
the circle has expanded. One can see, in historical record,
253
960000
4000
16:29
it expanding from the village, to the clan, to the tribe,
254
964000
3000
16:33
to the nation, to other races, to both sexes,
255
968000
3000
16:36
and, in Singer's own arguments, something that we should extend
256
971000
2000
16:38
to other sentient species. The question is,
257
973000
5000
16:43
if this has happened, what has powered that expansion?
258
978000
3000
16:46
And there are a number of possibilities, such as increasing circles
259
981000
3000
16:49
of reciprocity in the sense that Robert Wright argues for.
260
984000
4000
16:54
The logic of the golden rule -- the more you think about and interact
261
989000
4000
16:58
with other people, the more you realize that it is untenable
262
993000
4000
17:02
to privilege your interests over theirs,
263
997000
4000
17:06
at least not if you want them to listen to you. You can't say
264
1001000
3000
17:09
that my interests are special compared to yours,
265
1004000
3000
17:12
anymore than you can say that the particular spot
266
1007000
2000
17:15
that I'm standing on is a unique part of the universe
267
1010000
2000
17:18
because I happen to be standing on it that very minute.
268
1013000
2000
17:21
It may also be powered by cosmopolitanism, by histories,
269
1016000
4000
17:25
and journalism, and memoirs, and realistic fiction, and travel,
270
1020000
4000
17:29
and literacy, which allows you to project yourself into the lives
271
1024000
4000
17:33
of other people that formerly you may have treated as sub-human,
272
1028000
4000
17:37
and also to realize the accidental contingency of your own station
273
1032000
4000
17:41
in life, the sense that "there but for fortune go I."
274
1036000
3000
17:46
Whatever its causes, the decline of violence, I think,
275
1041000
3000
17:49
has profound implications. It should force us to ask not just, why
276
1044000
4000
17:53
is there war? But also, why is there peace? Not just,
277
1048000
4000
17:58
what are we doing wrong? But also, what have we been doing right?
278
1053000
3000
18:02
Because we have been doing something right,
279
1057000
1000
18:04
and it sure would be good to find out what it is.
280
1059000
2000
18:06
Thank you very much.
281
1061000
1000
18:07
(Applause).
282
1062000
11000
18:18
Chris Anderson: I loved that talk. I think a lot of people here in the room would say
283
1073000
4000
18:22
that that expansion of -- that you were talking about,
284
1077000
3000
18:25
that Peter Singer talks about, is also driven by, just by technology,
285
1080000
3000
18:28
by greater visibility of the other, and the sense that the world
286
1083000
4000
18:32
is therefore getting smaller. I mean, is that also a grain of truth?
287
1087000
3000
18:36
Steven Pinker: Very much. It would fit both in Wright's theory,
288
1091000
3000
18:40
that it allows us to enjoy the benefits of cooperation
289
1095000
3000
18:44
over larger and larger circles. But also, I think it helps us
290
1099000
3000
18:49
imagine what it's like to be someone else. I think when you read
291
1104000
3000
18:52
these horrific tortures that were common in the Middle Ages, you think,
292
1107000
3000
18:55
how could they possibly have done it,
293
1110000
2000
18:57
how could they have not have empathized with the person
294
1112000
2000
19:00
that they're disemboweling? But clearly,
295
1115000
2000
19:03
as far as they're concerned, this is just an alien being
296
1118000
3000
19:06
that does not have feelings akin to their own. Anything, I think,
297
1121000
3000
19:09
that makes it easier to imagine trading places
298
1124000
2000
19:12
with someone else means that it increases your moral consideration
299
1127000
3000
19:15
to that other person.
300
1130000
1000
19:16
CA: Well, Steve, I would love every news media owner to hear that talk
301
1131000
4000
19:20
at some point in the next year. I think it's really important. Thank you so much.
302
1135000
2000
19:22
SP: My pleasure.
303
1137000
1000
ABOUT THE SPEAKER
Steven Pinker - PsychologistSteven Pinker is a professor of cognitive science (the study of the human mind) who writes about language, mind and human nature.
Why you should listen
Steven Pinker grew up in the English-speaking community of Montreal but has spent his adult life bouncing back and forth between Harvard and MIT. He is interested in all aspects of human nature: how we see, hear, think, speak, remember, feel and interact.
To be specific: he developed the first comprehensive theory of language acquisition in children, used verb meaning as a window into cognition, probed the limits of neural networks and showed how the interaction between memory and computation shapes language. He has used evolution to illuminate innuendo, emotional expression and social coordination. He has documented historical declines in violence and explained them in terms of the ways that the violent and peaceable components of human nature interact in different eras. He has written books on the language instinct, how the mind works, the stuff of thought and the doctrine of the blank slate, together with a guide to stylish writing that is rooted in psychology.
In his latest book, Enlightenment Now: The Case for Reason, Science, Humanism, and Progress, he writes about progress -- why people are healthier, richer, safer, happier and better educated than ever. His other books include The Language Instinct, How the Mind Works, The Blank Slate: The Modern Denial of Human Nature, The Stuff of Thought, and The Better Angels of Our Nature.
Steven Pinker | Speaker | TED.com