1
00:00:03,880 --> 00:00:06,240
There are some great questions

2
00:00:06,240 --> 00:00:11,040
that have intrigued and haunted us
since the dawn of humanity.

3
00:00:12,960 --> 00:00:15,720
What is out there?

4
00:00:18,440 --> 00:00:21,120
How did we get here?

5
00:00:24,800 --> 00:00:27,200
What is the world made of?

6
00:00:30,200 --> 00:00:34,440
The story of our search
to answer those questions

7
00:00:34,440 --> 00:00:36,560
is the story of science.

8
00:00:37,560 --> 00:00:39,400
Of all human endeavours,

9
00:00:39,400 --> 00:00:42,840
science has had the greatest impact
on our lives,

10
00:00:42,840 --> 00:00:46,080
on how we see the world,
on how we see ourselves.

11
00:00:46,080 --> 00:00:52,760
Its ideas, its achievements,
its results are all around us.

12
00:00:52,760 --> 00:00:58,120
So how did we arrive
at the modern world?

13
00:00:59,640 --> 00:01:04,360
The answer is more surprising
and more human than you might think.

14
00:01:07,400 --> 00:01:10,960
It is a tale of power,

15
00:01:10,960 --> 00:01:13,640
proof,

16
00:01:13,640 --> 00:01:15,960
and passion.

17
00:01:23,640 --> 00:01:29,720
This time, one of the more intimate
questions we've ever asked.

18
00:01:29,720 --> 00:01:32,320
What makes us human?

19
00:01:54,320 --> 00:01:56,480
The question, what is human nature,

20
00:01:56,480 --> 00:02:00,400
what is it that shapes our thoughts,
feelings and desires,

21
00:02:00,400 --> 00:02:06,480
is one that philosophers,
writers and religious leaders
have all struggled with.

22
00:02:06,480 --> 00:02:12,520
I am particularly interested
in how science has wrestled
with this particular question,

23
00:02:12,520 --> 00:02:15,920
and that's not just because
it gets to the heart of who we are,

24
00:02:15,920 --> 00:02:20,880
but also because it gets to
the heart of what science itself is.

25
00:02:25,120 --> 00:02:31,040
I want to begin with
one of the great civilisations
of the ancient world -

26
00:02:31,040 --> 00:02:33,640
Egypt.

27
00:02:36,840 --> 00:02:40,880
The ancient Egyptians were amongst
the first people we know about

28
00:02:40,880 --> 00:02:45,240
to really wrestle with the question,
what makes us human?

29
00:02:49,480 --> 00:02:52,800
We humans are acutely aware
of ourselves,

30
00:02:52,800 --> 00:02:56,840
of the sense of being alive,
of living within our own skin.

31
00:02:56,840 --> 00:03:00,200
But where does this "me" reside?

32
00:03:00,200 --> 00:03:03,080
Where is the control centre?

33
00:03:03,080 --> 00:03:07,640
Where is the essence
of what I truly am?

34
00:03:09,280 --> 00:03:12,600
Egyptian beliefs
about what made us human

35
00:03:12,600 --> 00:03:16,600
are revealed in their attitudes
to the afterlife.

36
00:03:18,120 --> 00:03:21,320
Certain organs,
like the stomach, lungs or liver,

37
00:03:21,320 --> 00:03:26,560
were seen as so critical they were
frequently removed, embalmed,

38
00:03:26,560 --> 00:03:31,800
and put back inside the body
for burial.

39
00:03:33,440 --> 00:03:37,720
The Egyptians believed that the
heart was the key to the afterlife,

40
00:03:37,720 --> 00:03:42,840
that when you died it would testify
for your good or your bad deeds.

41
00:03:42,840 --> 00:03:46,800
On this papyrus you can see a heart
being weighed up against a feather.

42
00:03:46,800 --> 00:03:50,080
If it was heavier than the feather
then this demon over here

43
00:03:50,080 --> 00:03:52,840
would come and eat it,
and that was all over for you.

44
00:03:52,840 --> 00:03:59,080
In fact, the idea of being
light-hearted or heavy-hearted
comes from the Egyptians.

45
00:03:59,080 --> 00:04:04,120
And in a way you can understand
why they thought that the emotions
resided in the heart.

46
00:04:04,120 --> 00:04:09,600
Certainly when I have been
broken-hearted I've felt it
in my gut, and in my chest.

47
00:04:11,280 --> 00:04:16,640
So the Egyptians treated the heart
with great reverence.

48
00:04:16,640 --> 00:04:21,920
But what about that other organ
we now regard as more central
to our humanity?

49
00:04:26,880 --> 00:04:29,600
Here at Manchester University,

50
00:04:29,600 --> 00:04:35,000
a team of Egyptologists
are studying a 2,500-year-old mummy.

51
00:04:35,000 --> 00:04:39,040
An endoscope is going to be
pushed up its nose

52
00:04:39,040 --> 00:04:43,280
to show me how the Egyptians
treated the brain.

53
00:04:45,280 --> 00:04:48,080
Carefully.

54
00:04:49,520 --> 00:04:52,280
As we enter the nose

55
00:04:52,280 --> 00:04:54,720
through the nasal septum...

56
00:04:54,720 --> 00:04:57,200
How extraordinary.

57
00:04:59,360 --> 00:05:02,720
It's like going into some sort of
hidden cave. It is, isn't it?

58
00:05:02,720 --> 00:05:04,640
It's a secret world, really.

59
00:05:05,840 --> 00:05:09,680
We would normally be stopped from
going through there
because of the bone

60
00:05:09,680 --> 00:05:12,640
that would separate the brain
from the nasal cavity.

61
00:05:12,640 --> 00:05:16,200
Which should be there.
Yes, it should be there, of course.

62
00:05:16,200 --> 00:05:19,720
Right. And so now you're actually
entering the skull? Yes.

63
00:05:23,600 --> 00:05:25,400
Ooh!

64
00:05:25,400 --> 00:05:28,800
That's a sort of, a suture
in the top of the head, isn't it?

65
00:05:28,800 --> 00:05:32,720
There seems to be something missing.

66
00:05:32,720 --> 00:05:35,200
Yes, there's a brain missing.

67
00:05:35,200 --> 00:05:37,720
How extraordinary.

68
00:05:37,720 --> 00:05:40,440
Do they not see the brain
as important?

69
00:05:40,440 --> 00:05:44,880
They recognised that
the brain controlled
some of the bodily actions,

70
00:05:44,880 --> 00:05:49,560
but they certainly didn't think
that the individual personality

71
00:05:49,560 --> 00:05:51,440
was located in the brain.

72
00:05:51,440 --> 00:05:53,920
So they removed it and discarded it.

73
00:05:53,920 --> 00:05:56,240
So they just took it
and chucked it out. Yes. 

74
00:05:56,240 --> 00:06:02,280
It shows a certain contempt for
what we regard as one of our more
important organs now. Absolutely.

75
00:06:04,760 --> 00:06:10,840
The Egyptian concept of what makes
us who we are was a mystical union

76
00:06:10,840 --> 00:06:15,480
between the physical body
and an everlasting spirit.

77
00:06:19,600 --> 00:06:25,200
One of the recurring ideas to emerge
out of early civilisations
like the Egyptians

78
00:06:25,200 --> 00:06:29,280
was the belief that we are
more than simply flesh and blood.

79
00:06:29,280 --> 00:06:34,840
There is something else, something
which is special and makes us human.

80
00:06:34,840 --> 00:06:40,640
This conviction is one of
the most powerful and enduring
in human history.

81
00:06:44,680 --> 00:06:48,320
This belief shapes thinking
for millennia.

82
00:06:50,920 --> 00:06:53,480
But as Europe emerged
from the Middle Ages,

83
00:06:53,480 --> 00:06:56,760
people started to
approach the question differently.

84
00:06:59,240 --> 00:07:03,320
The physical and intellectual
frontiers of Europe were changing,

85
00:07:03,320 --> 00:07:08,000
and that would encourage
a very different view of who we are.

86
00:07:16,800 --> 00:07:22,920
That new view can be glimpsed here,
the grandest royal palace in France.

87
00:07:29,720 --> 00:07:34,200
Amongst this great splendour,
there's an intriguing technology...

88
00:07:35,720 --> 00:07:41,440
..that to me reflects a great change
in how we saw ourselves,

89
00:07:41,440 --> 00:07:44,560
captured in one magnificent room.

90
00:07:53,240 --> 00:07:57,240
And this is it. It's the great
hall of mirrors in Versailles.

91
00:08:02,600 --> 00:08:06,680
It is absolutely fantastic,

92
00:08:08,200 --> 00:08:12,240
and the whole room utterly dominated
by this wall of mirrors

93
00:08:12,240 --> 00:08:14,880
which extends down
almost 100 metres.

94
00:08:14,880 --> 00:08:17,720
I've never seen mirrors
on this scale.

95
00:08:36,440 --> 00:08:40,320
This really is
cutting-edge technology.

96
00:08:40,320 --> 00:08:44,760
Now this is not absolutely perfect,
the surface not completely smooth,

97
00:08:44,760 --> 00:08:47,400
you can see little bubbles here
in the glass.

98
00:08:47,400 --> 00:08:51,280
It's not perfect, it's not like
a sort of modern mirror.

99
00:08:51,280 --> 00:08:54,080
But the size and the scale
is unlike anything

100
00:08:54,080 --> 00:08:56,320
which was really done before,

101
00:08:56,320 --> 00:08:59,120
and compared to the sort of
curvy-wurvy things

102
00:08:59,120 --> 00:09:02,000
that most people would know of from
centuries earlier,

103
00:09:02,000 --> 00:09:05,080
this was something different.

104
00:09:05,080 --> 00:09:10,680
Because there was nothing,
nothing, nothing like this
had been developed before.

105
00:09:10,680 --> 00:09:13,240
It allowed people
to just stand there

106
00:09:13,240 --> 00:09:16,840
and look at themselves and think,
you know, "Who am I?" "This is me."

107
00:09:18,480 --> 00:09:22,680
These mirrors represent
the culmination of an idea

108
00:09:22,680 --> 00:09:25,640
that had been emerging in Europe
since the Renaissance.

109
00:09:28,240 --> 00:09:32,000
The notion that
we are all individuals.

110
00:09:32,000 --> 00:09:35,320
Not members of a class, or a guild,

111
00:09:35,320 --> 00:09:41,320
but defined by our own desires,
ambitions, and destinies.

112
00:09:44,560 --> 00:09:49,800
Along with this growing awareness
of self came different questions.

113
00:09:49,800 --> 00:09:52,320
What makes ME who I am?

114
00:09:52,320 --> 00:09:58,720
Why do I have these hopes,
these fears, these talents,
these expectations?

115
00:09:58,720 --> 00:10:03,360
And most importantly of all,
what is this "I" anyway?

116
00:10:12,520 --> 00:10:19,480
Throughout history, the technology
of the age has stimulated new ways
of looking at the world.

117
00:10:21,320 --> 00:10:23,080
I can see a thing which
looks a little bit...

118
00:10:23,080 --> 00:10:26,960
I don't know what it is,
it looks like some sort of
sea creature, possibly a prawn.

119
00:10:28,760 --> 00:10:35,160
New inventions have created
metaphors to help us think about
what makes us human.

120
00:10:36,880 --> 00:10:40,440
This makes me smile.

121
00:10:41,960 --> 00:10:45,760
In 17th-century France,
the philosopher Rene Descartes

122
00:10:45,760 --> 00:10:48,560
was wrestling with the question of
human nature.

123
00:10:50,640 --> 00:10:55,360
For inspiration, he drew on a
technological wonder of the age -

124
00:10:55,360 --> 00:10:58,200
water-powered mechanical statues.

125
00:11:04,280 --> 00:11:09,480
The story goes that Descartes is
wandering through the royal gardens

126
00:11:09,480 --> 00:11:15,280
and he sees a fountain, and in
the middle of the fountain there
is an enormous statue of Neptune,

127
00:11:15,280 --> 00:11:17,880
which is spouting water,
a bit like this.

128
00:11:17,880 --> 00:11:22,920
And this particular Neptune, when
you come close, sort of starts to
jab at you with the trident.

129
00:11:22,920 --> 00:11:26,880
And Descartes is rather taken by
this, and he starts to think,

130
00:11:26,880 --> 00:11:33,040
and he thinks perhaps animals
are just a form of automata,

131
00:11:33,040 --> 00:11:36,600
that perhaps a prawn
really has some sort of gears in it

132
00:11:36,600 --> 00:11:39,800
with lots of sort of
intersecting bits and pieces.

133
00:11:39,800 --> 00:11:43,760
And then he starts wondering,
perhaps that's what our bodies are,

134
00:11:43,760 --> 00:11:47,320
they're just sophisticated machines.

135
00:11:48,520 --> 00:11:52,240
For the time
this was a very daring idea,

136
00:11:52,240 --> 00:11:55,840
to suggest we are like machines,

137
00:11:55,840 --> 00:12:01,400
but it begged the question,
what special quality
actually makes us human?

138
00:12:05,440 --> 00:12:09,480
Descartes was a man
desperate for certainty,

139
00:12:09,480 --> 00:12:11,880
but this was no time to find it.

140
00:12:16,840 --> 00:12:21,640
17th-century Europe was riven by
religious and political conflict.

141
00:12:24,080 --> 00:12:28,560
Old certainties of
Church and State were crumbling.

142
00:12:28,560 --> 00:12:32,240
What, thought Descartes,
could he trust?

143
00:12:32,240 --> 00:12:36,080
What could he really know?

144
00:12:38,520 --> 00:12:40,800
Descartes is wracked by doubts,

145
00:12:40,800 --> 00:12:43,840
and he wants to find out
something he can believe in.

146
00:12:43,840 --> 00:12:47,120
Imagine, says Descartes, a tower,

147
00:12:47,120 --> 00:12:51,160
and the tower is in fact round,
but you perceive it as square.

148
00:12:51,160 --> 00:12:54,720
Or, for example, this thing here -
from a distance it looks square

149
00:12:54,720 --> 00:12:57,480
but actually when you hold it up
it is clearly round.

150
00:12:57,480 --> 00:12:59,320
Your vision has been deceived.

151
00:13:01,280 --> 00:13:06,360
And then Descartes wondered if
all his senses were deceiving him.

152
00:13:08,200 --> 00:13:11,640
He could feel
the warmth of his fire,

153
00:13:11,640 --> 00:13:15,240
see its light, hear its sound,

154
00:13:15,240 --> 00:13:20,320
but he'd experienced
the same sensations in a dream.

155
00:13:21,320 --> 00:13:26,560
So perhaps the whole world
he was living in
was nothing but an illusion.

156
00:13:30,760 --> 00:13:34,160
Descartes is now beginning to
really question everything -

157
00:13:34,160 --> 00:13:37,760
the moon, the sky, the stars.

158
00:13:37,760 --> 00:13:42,400
Perhaps they're all figments of his
imagination. But what about maths?

159
00:13:42,400 --> 00:13:45,400
Two plus three -
it always equals five, doesn't it?

160
00:13:45,400 --> 00:13:49,680
But maybe there's a demon who's
taken possession of his brain.

161
00:13:49,680 --> 00:13:54,080
Descartes is really
beginning to doubt everything,

162
00:13:54,080 --> 00:14:01,120
down to the very question of
whether he himself existed at all.

163
00:14:05,360 --> 00:14:07,920
And then, finally, he got there.

164
00:14:07,920 --> 00:14:11,920
He realised that the act of doubting
implied a doubter.

165
00:14:11,920 --> 00:14:14,760
There was one thing he could
be absolutely certain of -

166
00:14:14,760 --> 00:14:19,640
the existence of his own
thinking, doubting mind.

167
00:14:19,640 --> 00:14:26,720
He summed it up in a neat
philosophical phrase -
"I think, therefore I am".

168
00:14:29,080 --> 00:14:35,080
It may be a familiar phrase,
but it contains a profound idea -

169
00:14:35,080 --> 00:14:39,600
the claim that the essence of our
humanity lies in our thoughts,

170
00:14:39,600 --> 00:14:41,880
our ability to reason.

171
00:14:41,880 --> 00:14:47,320
And reason was to form the basis
of a new, experimental science.

172
00:14:56,680 --> 00:15:02,120
Across the Channel,
a much more bloody approach
to the question of "Who are we?"

173
00:15:02,120 --> 00:15:05,040
was to emerge from
a great political clash -

174
00:15:07,840 --> 00:15:10,680
the English Civil War.

175
00:15:10,680 --> 00:15:13,280
Oxford was a key
Royalist stronghold.

176
00:15:13,280 --> 00:15:18,200
For some caught up in the action,
turmoil spelt opportunity.

177
00:15:22,200 --> 00:15:26,600
Here in Oxford, a young man called
Thomas Willis was part way through

178
00:15:26,600 --> 00:15:32,560
his medical training, which in those
days lasted an incredible 14 years.

179
00:15:32,560 --> 00:15:35,240
The Civil War
interrupted his studies,

180
00:15:35,240 --> 00:15:37,880
which in many ways
was a very good thing.

181
00:15:40,800 --> 00:15:46,280
Studying medicine didn't
necessarily make you a good doctor,

182
00:15:46,280 --> 00:15:48,600
for one very good reason.

183
00:15:50,800 --> 00:15:56,440
Medical teaching was still largely
based on ideas from antiquity.

184
00:15:56,440 --> 00:16:03,720
The disruption of his studies
gave Willis the opportunity
to investigate the body for himself.

185
00:16:05,360 --> 00:16:10,560
By now, people were exploring
the anatomy of the brain.

186
00:16:10,560 --> 00:16:14,640
But still,
no-one really knew what it did.

187
00:16:17,280 --> 00:16:23,960
In the mid-1600s,
Willis began a ground-breaking
series of dissections,

188
00:16:23,960 --> 00:16:28,560
and I'm about to get a privileged
glimpse of what he would have seen.

189
00:16:30,600 --> 00:16:34,800
Ah! There we are. Human brain.
Isn't it wonderful? It is.

190
00:16:34,800 --> 00:16:42,040
It is utterly unbelievable
when you think that this brain
once thought, it reasoned.

191
00:16:42,040 --> 00:16:45,800
It's a unique feature
of the universe, really.

192
00:16:47,040 --> 00:16:50,080
When a brain is sort of fresh
it's a very different consistency.

193
00:16:50,080 --> 00:16:53,560
Yes, it is, it's... I tell students
it's a bit like a badly set jelly.

194
00:16:53,560 --> 00:16:57,360
But presumably if you were
to cut that you really would
have great difficulties.

195
00:16:57,360 --> 00:17:00,000
Yes, it would just
fall to pieces, really.

196
00:17:01,320 --> 00:17:05,400
Willis was one of the first
o use a new technique -

197
00:17:07,480 --> 00:17:10,040
preserving brains in alcohol.

198
00:17:10,040 --> 00:17:14,560
This made them firm enough
to dissect with great precision.

199
00:17:16,560 --> 00:17:18,920
You ready to cut this?
Yes, ready to cut.

200
00:17:27,200 --> 00:17:28,840
Isn't it strange?

201
00:17:32,040 --> 00:17:33,880
Ah!

202
00:17:33,880 --> 00:17:40,640
What's really curious is that
there's almost no structure
or definition to it, is there?

203
00:17:40,640 --> 00:17:44,640
The thing that really catches your
eye is the ventricles in the centre,

204
00:17:44,640 --> 00:17:48,960
which were what everybody was
preoccupied with before Willis.

205
00:17:48,960 --> 00:17:55,320
And the idea was that this part of
the brain may have acted as
a sort of pump,

206
00:17:55,320 --> 00:18:01,040
and important activities
may have gone on in the fluid that
was moving around in the ventricles.

207
00:18:01,040 --> 00:18:04,560
So in a sense all this is just
muscle, and all the thought

208
00:18:04,560 --> 00:18:07,680
and the important stuff is taking
place in these holes over here?

209
00:18:07,680 --> 00:18:09,960
Yes, and it was Thomas Willis
who realised that

210
00:18:09,960 --> 00:18:13,160
the actual structure of the brain
was what was critically important.

211
00:18:14,680 --> 00:18:19,200
When Willis looked at animal brains,
he concluded our intellect

212
00:18:19,200 --> 00:18:25,120
and thoughts must lie in the parts
of the brain animals don't possess.

213
00:18:25,120 --> 00:18:30,160
Thomas Willis was very struck by the
corrugated surface of the human brain

214
00:18:30,160 --> 00:18:33,960
as compared to the smooth surface
of the sheep, and this enables

215
00:18:33,960 --> 00:18:37,000
a huge volume of cerebral cortex
to be contained

216
00:18:37,000 --> 00:18:40,240
within the relatively
small volume of the skull.

217
00:18:40,240 --> 00:18:43,880
And that's where he thought
being human resided? Yes.

218
00:18:43,880 --> 00:18:47,720
You can see there's a ribbon of
cortex going over the surface

219
00:18:47,720 --> 00:18:51,400
of the cerebral hemispheres.
Oh, just there. Yes, that's right.

220
00:18:51,400 --> 00:18:57,440
And this cortex was
where he realised people were
likely to have their thoughts.

221
00:19:00,040 --> 00:19:05,720
Willis had established a link
between the state of the brain
and the state of the mind.

222
00:19:07,400 --> 00:19:12,600
He wrote the first book
specifically about the brain.

223
00:19:12,600 --> 00:19:16,440
From now on, anatomical studies
would become

224
00:19:16,440 --> 00:19:22,880
one of the great foundations
of a scientific explanation
of who we are.

225
00:19:32,400 --> 00:19:36,680
Reason was now seen as
the pinnacle of human nature.

226
00:19:36,680 --> 00:19:40,240
It had been shaped
by philosophical doubt,

227
00:19:40,240 --> 00:19:43,160
and detailed dissections
of the brain.

228
00:19:45,320 --> 00:19:50,440
Europe entered a new age,
a celebration of the rational mind.

229
00:19:53,280 --> 00:19:57,640
Faith in reason
would underpin the growth of trade

230
00:19:57,640 --> 00:20:00,200
and the building of empires.

231
00:20:08,120 --> 00:20:14,040
In 1837, something was
causing a stir at London Zoo.

232
00:20:16,760 --> 00:20:19,640
Their first orang-utan, Jenny,

233
00:20:19,640 --> 00:20:22,720
was introduced to
an astonished audience.

234
00:20:24,920 --> 00:20:29,440
Exotic animals were being brought
to Britain from across the Empire.

235
00:20:34,320 --> 00:20:38,480
Even Queen Victoria herself
came calling.

236
00:20:42,000 --> 00:20:48,440
Jenny's arrival
would challenge assumptions
about what makes us human.

237
00:20:48,440 --> 00:20:52,800
Right, come this way, Michael,
I'll introduce you to Batu,

238
00:20:52,800 --> 00:20:55,400
who should be waiting. There he is.

239
00:20:55,400 --> 00:20:59,320
There he is. Hello. This is Batu.
Wow, he's big.

240
00:20:59,320 --> 00:21:01,640
Hello. Batu's very big.

241
00:21:01,640 --> 00:21:04,360
What a beautiful face.
Very big and very strong.

242
00:21:04,360 --> 00:21:07,960
Right. Can I do this? Yeah,
just be careful with the orange.

243
00:21:07,960 --> 00:21:09,840
Yeah.

244
00:21:09,840 --> 00:21:12,200
Oop, very delicately done!

245
00:21:12,200 --> 00:21:13,840
He doesn't want to drop it.

246
00:21:15,440 --> 00:21:18,280
He's even ruder than my kids!

247
00:21:20,080 --> 00:21:21,400
That's rude, stop it.

248
00:21:21,400 --> 00:21:24,840
You could actually see a wonderfully
sort of sullen look on his face.

249
00:21:24,840 --> 00:21:27,320
Yeah.
That look of "Mm, don't like that."

250
00:21:27,320 --> 00:21:29,960
It's a very human expression.

251
00:21:31,160 --> 00:21:35,120
Odd behaviour.
Oh, no, that's terrible!

252
00:21:35,120 --> 00:21:37,800
Ah! Ugh!

253
00:21:37,800 --> 00:21:42,480
It's wonderful, this is a,
a great sense of independence.

254
00:21:42,480 --> 00:21:44,680
Stop it now.

255
00:21:44,680 --> 00:21:46,840
You've spat at me.

256
00:21:46,840 --> 00:21:48,400
You've played your game.

257
00:21:48,400 --> 00:21:50,240
What are you going to do next?

258
00:21:52,240 --> 00:21:54,400
Oh, that's smelly!

259
00:22:00,120 --> 00:22:05,280
One of the visitors to the zoo
was young Charles Darwin.

260
00:22:06,320 --> 00:22:09,800
But this isn't
the familiar story about evolution.

261
00:22:12,480 --> 00:22:16,600
His visit to the zoo was part of
his lesser-known research -

262
00:22:19,480 --> 00:22:22,800
fascination with animal emotion.

263
00:22:24,720 --> 00:22:28,600
One day, Darwin saw something
that really astonished him.

264
00:22:30,560 --> 00:22:35,360
Jenny was playing with the keeper,
and the keeper had an apple,

265
00:22:35,360 --> 00:22:41,600
and the keeper was taunting Jenny
by waving the apple in front of her
but not letting her get hold of it.

266
00:22:41,600 --> 00:22:47,640
And in Darwin's words, "The ape
threw herself on her back and cried
precisely like a little child."

267
00:22:52,160 --> 00:22:56,240
Darwin became convinced
that the expressions of emotion

268
00:22:56,240 --> 00:23:01,080
he saw in Jenny
and in humans were the same.

269
00:23:01,080 --> 00:23:04,520
His research
developed over 30 years.

270
00:23:07,920 --> 00:23:11,680
Tenderness, shame, joy -

271
00:23:11,680 --> 00:23:14,640
he saw them all in animals.

272
00:23:18,960 --> 00:23:22,920
Darwin's painstaking work led to
one of his most important books,

273
00:23:22,920 --> 00:23:28,920
The Expression Of The Emotions
In Man And Animals.

274
00:23:28,920 --> 00:23:32,320
It was greeted with alarm
and fascination.

275
00:23:32,320 --> 00:23:35,560
Now this is a really
incredible book,

276
00:23:35,560 --> 00:23:40,960
partly because of the illustrations,
because this is one of the first
books ever to include photographs.

277
00:23:40,960 --> 00:23:45,280
And they feature people,
people in various states
of distress, if you like.

278
00:23:45,280 --> 00:23:49,040
Disconsolate, sad, very sad-looking.

279
00:23:49,040 --> 00:23:51,640
He examines it
in almost microscopic detail.

280
00:23:51,640 --> 00:23:56,160
There's a very interesting picture
here of a woman's forehead,

281
00:23:56,160 --> 00:23:58,720
and he notices these two lines
coming up here,

282
00:23:58,720 --> 00:24:02,040
which were later called
in fact the Darwin grief muscle.

283
00:24:04,880 --> 00:24:10,360
What Darwin was undermining in
his work was a fundamental belief -

284
00:24:11,880 --> 00:24:15,120
a belief in human uniqueness.

285
00:24:24,240 --> 00:24:27,280
By suggesting a close kinship
with animals,

286
00:24:27,280 --> 00:24:30,840
he'd also opened the lid
on the rational mind,

287
00:24:30,840 --> 00:24:37,120
hinting at a dark subterranean world
of instincts, desires, emotions -

288
00:24:37,120 --> 00:24:38,800
the animal within.

289
00:24:43,520 --> 00:24:47,720
Here was an irony for
Victorian science.

290
00:24:47,720 --> 00:24:51,360
The power of reason,
which made us unique,

291
00:24:51,360 --> 00:24:54,000
had been turned on ourselves,

292
00:24:54,000 --> 00:24:58,520
and revealed us to be
less exalted, less rational,

293
00:24:58,520 --> 00:25:00,840
than had been suspected.

294
00:25:09,760 --> 00:25:14,480
A new side of ourselves
was being unearthed,

295
00:25:14,480 --> 00:25:18,360
darker and more dangerous.

296
00:25:21,280 --> 00:25:27,120
In Paris, doctors began to
explore this untamed side,

297
00:25:29,120 --> 00:25:31,520
at La Salpetriere.

298
00:25:33,240 --> 00:25:38,320
This imposing-looking building was
originally used to store gunpowder,

299
00:25:38,320 --> 00:25:41,800
but then they decided
they could put it to better use,

300
00:25:41,800 --> 00:25:45,000
to lock away thousands of people
who were regarded as just as

301
00:25:45,000 --> 00:25:49,600
unstable and dangerous -
the destitute and the insane.

302
00:25:55,720 --> 00:26:00,160
It had been Europe's most notorious
women's asylum,

303
00:26:00,160 --> 00:26:04,120
with nothing to offer
but cruel imprisonment.

304
00:26:07,800 --> 00:26:11,160
These are some of the cells
where they kept the women,

305
00:26:11,160 --> 00:26:16,160
and these are the original bars
behind which they were imprisoned.

306
00:26:16,160 --> 00:26:23,120
And there is something
terribly poignant about the idea of
thousands of women chained up,

307
00:26:23,120 --> 00:26:26,280
in filthy living conditions,

308
00:26:26,280 --> 00:26:33,280
utterly without any prospect of
release, no hope, no hope at all.

309
00:26:37,440 --> 00:26:40,760
But attitudes were changing.

310
00:26:40,760 --> 00:26:45,800
After years of revolution, the
asylum had become a place of care

311
00:26:45,800 --> 00:26:48,040
rather than simply imprisonment.

312
00:26:51,120 --> 00:26:56,120
One of its most famous physicians
was Jean-Martin Charcot.

313
00:26:58,920 --> 00:27:04,960
Often the best way to understand
the normal is to study the abnormal,

314
00:27:04,960 --> 00:27:10,720
and here there were 5,000
troubled minds to study.

315
00:27:12,320 --> 00:27:16,280
Charcot was one of the first people
to try and separate out

316
00:27:16,280 --> 00:27:20,320
and categorise different forms of
mental and neurological illness.

317
00:27:20,320 --> 00:27:26,360
He took incredibly detailed notes,
and he also took
lots of photographs.

318
00:27:28,040 --> 00:27:32,640
One condition in particular
had been puzzling doctors.

319
00:27:34,840 --> 00:27:38,000
They called it hysteria.

320
00:27:38,280 --> 00:27:44,720
Patients suffered paralysis,
seizures, blindness,
and violent fits.

321
00:27:44,720 --> 00:27:49,920
Charcot presumed these symptoms
were caused by a physical disease,

322
00:27:49,920 --> 00:27:57,120
but then he began to use
a remarkable new approach.

323
00:27:57,120 --> 00:28:00,360
Five, six...

324
00:28:00,360 --> 00:28:01,680
Hypnosis.

325
00:28:01,680 --> 00:28:04,120
..Seven...

326
00:28:04,120 --> 00:28:07,640
Charcot found
he could induce and relieve

327
00:28:07,640 --> 00:28:10,840
symptoms of hysteria using hypnosis.

328
00:28:10,840 --> 00:28:13,880
And become aware of any
feelings of lightness, going up.

329
00:28:13,880 --> 00:28:18,680
It could produce extraordinary
effects in the body.

330
00:28:18,680 --> 00:28:24,880
Drifting up and up now, and the
balloon really sort of taking off
now and bobbing from side to side.

331
00:28:24,880 --> 00:28:27,440
OK, can you see the balloon?

332
00:28:27,440 --> 00:28:29,480
I can, it's a big blue balloon.

333
00:28:29,480 --> 00:28:32,440
OK, and it's... A sort of
Winnie the Pooh blue balloon.

334
00:28:32,440 --> 00:28:34,960
OK. Well, you get that feeling
of the...

335
00:28:34,960 --> 00:28:41,240
'I've tried hypnosis before,
but this is the first time
it's really worked.'

336
00:28:41,240 --> 00:28:44,080
OK and just notice
what's happening there.

337
00:28:44,080 --> 00:28:48,120
'Over the course of an hour,
I mysteriously lost
co-ordination of my hand.'

338
00:28:48,120 --> 00:28:53,680
And that's even more noticeable in
fact, it's becoming really shaky now.

339
00:28:53,680 --> 00:28:57,040
'I had my hands stuck together.'

340
00:28:57,040 --> 00:28:58,880
Knuckles are quite locked.

341
00:28:58,880 --> 00:29:00,480
Oh! They are quite locked.

342
00:29:00,480 --> 00:29:06,880
'And most bizarre at all,
one side of my visual field
was rendered almost useless.'

343
00:29:06,880 --> 00:29:09,040
Seems a bit fainter. OK.

344
00:29:09,040 --> 00:29:12,640
And, um, I have a sense of
something in there but not really.

345
00:29:12,640 --> 00:29:15,400
OK. Not really objects. OK.

346
00:29:15,400 --> 00:29:18,120
One, two...

347
00:29:18,120 --> 00:29:20,680
'That was extremely odd.'

348
00:29:20,680 --> 00:29:24,280
It was a bit like I was there
but I wasn't there,

349
00:29:24,280 --> 00:29:27,120
that he was talking to
some other part of me,

350
00:29:27,120 --> 00:29:30,560
and the other part of me
was responding.

351
00:29:30,560 --> 00:29:35,640
Higher, and higher.
And the idea you can just do it
with the power of words...

352
00:29:35,640 --> 00:29:38,360
quite strange.

353
00:29:40,360 --> 00:29:43,880
Charcot's observations of hysteria
led him towards

354
00:29:43,880 --> 00:29:45,400
a radical conclusion.

355
00:29:49,240 --> 00:29:53,600
If symptoms could be induced
or relieved by hypnosis,

356
00:29:53,600 --> 00:29:57,880
then perhaps they were not signs of
some pathological disease.

357
00:29:57,880 --> 00:30:00,080
Perhaps they were caused
by emotions,

358
00:30:00,080 --> 00:30:04,040
that the patients themselves were
not even aware they were feeling.

359
00:30:04,040 --> 00:30:07,560
Charcot never fully grasped
what he was dealing with,

360
00:30:07,560 --> 00:30:11,400
what we would now call
the unconscious mind.

361
00:30:14,480 --> 00:30:18,400
In amongst the crowds at one of
Charcot's famous demonstrations

362
00:30:18,400 --> 00:30:22,720
was a young Austrian doctor,
Sigmund Freud,

363
00:30:24,240 --> 00:30:29,000
a man who would famously use
the study of hidden emotions

364
00:30:29,000 --> 00:30:33,840
and repressed urges to develop
this extraordinary concept

365
00:30:33,840 --> 00:30:35,960
of the unconscious mind.

366
00:30:37,840 --> 00:30:42,160
Freud's ideas would become
a significant cultural influence

367
00:30:42,160 --> 00:30:43,680
on the 20th century.

368
00:30:47,040 --> 00:30:51,000
They would join a rising tide
of other ideas

369
00:30:51,000 --> 00:30:57,160
that would form a wholly new
approach to who we are - psychology.

370
00:31:06,040 --> 00:31:09,560
A less than rational self
had been revealed -

371
00:31:12,240 --> 00:31:15,880
by animals
brought back from distant lands,

372
00:31:18,000 --> 00:31:21,960
by changing attitudes
to mental illness,

373
00:31:21,960 --> 00:31:25,200
and a new door
into the unconscious mind.

374
00:31:26,720 --> 00:31:31,440
We could no longer see ourselves
simply as creatures of reason.

375
00:31:42,200 --> 00:31:44,400
By the end of the 19th century,

376
00:31:44,400 --> 00:31:48,880
Europe was in the throes of
a bold new age of communication.

377
00:31:57,600 --> 00:32:04,080
Thousands of miles of new railway
linked the continent's great cities.

378
00:32:04,080 --> 00:32:07,960
Telegraph cables joined people
across the globe.

379
00:32:13,680 --> 00:32:16,680
This interconnected world

380
00:32:16,680 --> 00:32:23,160
led to a different way
of looking at how the brain works.

381
00:32:23,160 --> 00:32:26,360
This new technology,
naturally enough,

382
00:32:26,360 --> 00:32:30,720
inspired new metaphors
to describe the nervous system.

383
00:32:30,720 --> 00:32:34,880
For example, if I pinch my finger,
then the pain fibres go

384
00:32:34,880 --> 00:32:38,640
down the line, up into my spinal
cord and from there to the brain.

385
00:32:38,640 --> 00:32:41,000
The thing is, what happens next?

386
00:32:41,000 --> 00:32:45,280
Well, everyone knew there were
complicated signal boxes
and junctions up there,

387
00:32:45,280 --> 00:32:48,040
but nobody knew
just how they worked.

388
00:32:56,120 --> 00:32:58,080
The Spanish countryside.

389
00:33:03,640 --> 00:33:06,840
Home to a scientist I deeply admire.

390
00:33:07,960 --> 00:33:13,640
He had a passion for art
that would shape his future career
as a neuroscientist.

391
00:33:18,360 --> 00:33:23,040
His name
was Santiago Ramon y Cajal.

392
00:33:27,040 --> 00:33:31,960
When he was a young man,
Cajal was obsessed by art.

393
00:33:31,960 --> 00:33:36,160
As he later wrote, "I was gripped
by an irresistible mania.

394
00:33:36,160 --> 00:33:43,600
"I painted everything that
captivated my sight - earth,
foliage, plants, the human form".

395
00:33:43,600 --> 00:33:47,840
He was actually extremely good at
putting down on paper what he saw.

396
00:33:49,360 --> 00:33:51,400
Cajal's passion for art

397
00:33:51,400 --> 00:33:57,400
was coupled with a fascination
for a new technology - photography.

398
00:33:57,400 --> 00:34:01,320
This is the sort of camera
that Cajal would have used.

399
00:34:01,320 --> 00:34:03,960
I've got it lined up
on the mountains now.

400
00:34:03,960 --> 00:34:07,000
I've got a photographic plate
in here,

401
00:34:07,000 --> 00:34:10,760
which is basically
a bit of glass with some
photosensitive chemicals on.

402
00:34:10,760 --> 00:34:12,640
And then you lift this.

403
00:34:12,640 --> 00:34:16,800
And you trigger the shutter.

404
00:34:16,800 --> 00:34:19,560
It should take about 20 seconds.

405
00:34:19,560 --> 00:34:21,720
When that's done, this goes down,

406
00:34:21,720 --> 00:34:24,040
and the glass plate
you take away with you

407
00:34:24,040 --> 00:34:26,160
off to the mysteries
of the darkroom.

408
00:34:32,640 --> 00:34:36,480
It was his twin passions, art
and photography, that would shape

409
00:34:36,480 --> 00:34:41,360
his most important discovery - what
it is that makes the brain work.

410
00:34:45,120 --> 00:34:48,760
To see, observe,
and make things visible

411
00:34:48,760 --> 00:34:52,520
is one of the great challenges
of science.

412
00:34:52,520 --> 00:34:55,080
The challenge for neuroscientists

413
00:34:55,080 --> 00:34:58,680
was uncovering the fine structure
of the brain.

414
00:35:00,200 --> 00:35:06,080
The task Cajal set himself was to
reveal the communication networks

415
00:35:06,080 --> 00:35:08,640
that exist inside our heads.

416
00:35:10,840 --> 00:35:15,400
I've come to the Cajal Institute
to see how he did it.

417
00:35:15,400 --> 00:35:20,160
I always feel like I'm getting into
surgery again. Great.

418
00:35:20,160 --> 00:35:23,600
So...mouse? Yeah, take the brain.

419
00:35:23,600 --> 00:35:28,760
'My first job is to chop up
a rather slippery mouse brain.'

420
00:35:28,760 --> 00:35:31,520
Very small. Hey!

421
00:35:31,520 --> 00:35:34,280
'It's trickier than it looks'.

422
00:35:34,280 --> 00:35:36,000
There we go.

423
00:35:36,000 --> 00:35:38,920
Feels like cutting onions. Yes!

424
00:35:38,920 --> 00:35:40,960
I'm good at cutting onions.

425
00:35:45,200 --> 00:35:48,400
'The search was on for a stain
that would make the mysterious

426
00:35:48,400 --> 00:35:51,880
'structure of the brain
visible under the microscope.'

427
00:35:55,000 --> 00:35:59,720
'Cajal was shown a technique
using chemicals from the darkroom,

428
00:35:59,720 --> 00:36:02,720
'chemicals that could make
brain tissue turn black'

429
00:36:02,720 --> 00:36:07,800
You can see
it's a really complicated process,

430
00:36:07,800 --> 00:36:09,960
lots of different stages.

431
00:36:11,480 --> 00:36:15,280
Cajal spent nearly 20 years
fiddling away,

432
00:36:15,280 --> 00:36:18,760
doing minor adjustments,
just seeking perfection.

433
00:36:19,920 --> 00:36:25,000
The great debate was whether the
brain was just a mesh of fibres,

434
00:36:25,000 --> 00:36:28,400
or made of
distinct individual units.

435
00:36:36,200 --> 00:36:42,200
Placing stained tissue under the
microscope, Cajal became convinced

436
00:36:42,200 --> 00:36:47,760
that there were individual building
blocks in the brain - neurons.

437
00:36:50,680 --> 00:36:54,360
Now, that is absolutely beautiful.

438
00:36:57,000 --> 00:36:58,880
That is a neuron.

439
00:36:58,880 --> 00:37:01,720
That is what they were looking for.

440
00:37:01,720 --> 00:37:04,760
Now, the signal goes up here
into the cell body,

441
00:37:04,760 --> 00:37:10,440
and then somehow gets distributed
by thousands of axons and dendrites,

442
00:37:10,440 --> 00:37:13,240
which link in with
all the other neurons in the brain.

443
00:37:13,240 --> 00:37:18,520
Now, only about 1 in 40 of
the neurons actually get stained,

444
00:37:18,520 --> 00:37:22,520
and that might sound like
a bad thing, but it's actually
an incredibly good thing

445
00:37:22,520 --> 00:37:25,240
because if all the neurons here
were stained,

446
00:37:25,240 --> 00:37:27,440
then this would be
a confusing mass.

447
00:37:27,440 --> 00:37:29,800
You wouldn't be able to
make any sense at all.

448
00:37:30,240 --> 00:37:33,520
But because it's just 1 in 40,
you can pick them out.

449
00:37:40,000 --> 00:37:43,600
You can see Cajal's
artistic influence here -

450
00:37:43,600 --> 00:37:47,800
beautiful drawings of neurons.

451
00:37:52,160 --> 00:37:55,240
He mapped out groups of neurons,

452
00:37:55,240 --> 00:37:58,000
and theorised how they might work -

453
00:37:59,760 --> 00:38:04,880
that nerve impulses
travel along them in one direction,

454
00:38:04,880 --> 00:38:08,160
passing from one cell to the next.

455
00:38:11,360 --> 00:38:15,440
Many years later,
his theories would be confirmed.

456
00:38:17,200 --> 00:38:22,040
Cajal realised that these neurons
are the basic units
of the human brain.

457
00:38:22,040 --> 00:38:25,720
We now know there are at least
a hundred billion of them,

458
00:38:25,720 --> 00:38:29,920
and all these connecting branches,
well, there are trillions
of connections.

459
00:38:29,920 --> 00:38:35,160
And somewhere in here,
emotion and thought are born.

460
00:38:35,160 --> 00:38:40,320
Somewhere in here
is the answer to what makes a human.

461
00:38:54,080 --> 00:38:58,360
Half a century later,
the world descended into chaos.

462
00:39:02,480 --> 00:39:07,080
Out of the turmoil of World War II
came a secret invention,

463
00:39:07,080 --> 00:39:10,680
built here at Bletchley Park
in rural England.

464
00:39:13,200 --> 00:39:21,080
Colossus - the most complex machine
that had yet been built.

465
00:39:21,080 --> 00:39:23,800
Designed to crack enemy codes,

466
00:39:23,800 --> 00:39:28,560
it would also shed light
on the question of who we are.

467
00:39:28,560 --> 00:39:32,600
What was truly astonishing
about Colossus

468
00:39:32,600 --> 00:39:35,360
was the speed
at which it could work.

469
00:39:35,360 --> 00:39:39,480
Enemy messages which had previously
taken teams of human code-breakers

470
00:39:39,480 --> 00:39:44,920
six weeks to crack could now be done
by the machine in six hours.

471
00:39:44,920 --> 00:39:48,160
It must have seemed
truly superhuman.

472
00:39:50,680 --> 00:39:54,040
Here was a machine
doing something that till now

473
00:39:54,040 --> 00:39:59,040
only the intelligent human mind
could do, but much faster.

474
00:40:00,760 --> 00:40:03,720
Once again,
the technology of the day

475
00:40:03,720 --> 00:40:07,240
offered a model
for how the brain might work.

476
00:40:10,040 --> 00:40:13,760
When you think about it,
it's a bit like a primitive brain,

477
00:40:13,760 --> 00:40:16,080
with the valves
representing the neurons

478
00:40:16,080 --> 00:40:20,160
and the wiring representing
the connecting axons and dendrites.

479
00:40:29,080 --> 00:40:32,560
People had begun to theorise
that Cajal's neurons

480
00:40:32,560 --> 00:40:35,920
worked a bit like
electronic switches.

481
00:40:36,880 --> 00:40:41,560
If intelligence could be replicated
by the on-off switching
of a machine,

482
00:40:41,560 --> 00:40:46,880
perhaps the reasoning mind wasn't
as uniquely human as we thought.

483
00:40:50,440 --> 00:40:54,400
One of the biggest human brains
at Bletchley was Alan Turing,

484
00:40:54,400 --> 00:40:57,880
often called
the father of modern computing.

485
00:40:57,880 --> 00:41:03,040
In 1950, he thought of an ingenious
way of judging whether computers

486
00:41:03,040 --> 00:41:07,920
show some form of intelligence,
by devising a test.

487
00:41:09,200 --> 00:41:13,360
The Turing test is actually
more of a Turing question.

488
00:41:13,360 --> 00:41:15,360
The question he asked himself was,

489
00:41:15,360 --> 00:41:19,720
would it be possible to build
a computer that was so intelligent

490
00:41:19,720 --> 00:41:22,360
and so good at
having chats with humans

491
00:41:22,360 --> 00:41:24,760
that you could be chatting
to the machine

492
00:41:24,760 --> 00:41:28,480
and not be aware that you're not
actually talking to another person?

493
00:41:28,480 --> 00:41:33,160
Well, he suggested that
by the year 2000,
we would have cracked the problem.

494
00:41:33,160 --> 00:41:36,080
We are well beyond that point.
Let's see.

495
00:41:37,240 --> 00:41:41,640
Right, "what is your name?"

496
00:41:41,640 --> 00:41:45,560
You don't remember?
No, I don't remember.

497
00:41:45,560 --> 00:41:50,200
'I'm plugged into one of
the more sophisticated programs,

498
00:41:50,200 --> 00:41:54,000
'designed to respond to
Turing's challenge.'

499
00:41:54,000 --> 00:41:56,280
OK, let's try some,
er, general knowledge.

500
00:41:56,280 --> 00:41:59,880
I mean, computers should be able to
do general knowledge.

501
00:41:59,880 --> 00:42:04,040
'It doesn't ever
seem to really answer the question.'

502
00:42:04,040 --> 00:42:06,120
Anyway, this is garbage.

503
00:42:06,120 --> 00:42:10,560
'Let's try a different tack -
favourite films.'

504
00:42:10,560 --> 00:42:13,440
Transformers 2.

505
00:42:13,440 --> 00:42:15,640
Maybe that is some sort of
computer joke.

506
00:42:15,640 --> 00:42:18,120
I can't believe anybody
liked Transformers 2.

507
00:42:18,120 --> 00:42:23,840
"What films make you cry?"

508
00:42:26,480 --> 00:42:29,360
"Science fiction and comedy.
What do you like?"

509
00:42:29,360 --> 00:42:31,560
Right. It's not very impressive.

510
00:42:31,560 --> 00:42:35,080
I'm not enjoying myself. I'm not
having a great conversation here.

511
00:42:37,680 --> 00:42:41,680
I think what you can learn
from this is that computers
are good at computing,

512
00:42:41,680 --> 00:42:44,560
basically, crunching numbers
and things like that.

513
00:42:44,560 --> 00:42:47,520
What they clearly lack
is the thing that

514
00:42:47,520 --> 00:42:52,280
really gives any form of human
interchange any worth, any value -

515
00:42:52,280 --> 00:42:56,840
feelings like humour, warmth,
love, affection,

516
00:42:56,840 --> 00:43:00,680
any of the things
that we actually value.

517
00:43:00,680 --> 00:43:04,440
Perhaps too much to expect
from a machine.

518
00:43:04,440 --> 00:43:08,840
Bye bye.
ELECTRONIC VOICE: Goodbye. Goodbye.

519
00:43:11,680 --> 00:43:16,560
For centuries, technology
has provided metaphors
to explain who we are.

520
00:43:16,560 --> 00:43:20,640
The computer is simply the latest
we have seized on.

521
00:43:20,640 --> 00:43:23,520
But its failings
reveal that what makes us human

522
00:43:23,520 --> 00:43:25,880
lies in something
a machine cannot do.

523
00:43:28,440 --> 00:43:32,160
We are passionate,
irrational creatures,

524
00:43:32,160 --> 00:43:35,720
often driven by forces
we do not understand.

525
00:43:47,360 --> 00:43:51,960
At the turn of the 20th century,
a great nation was coming of age.

526
00:43:57,640 --> 00:44:00,080
The United States.

527
00:44:12,120 --> 00:44:16,320
The land of the free,
personal rights and liberties.

528
00:44:19,000 --> 00:44:22,840
This was the perfect home
for the thriving discipline

529
00:44:22,840 --> 00:44:29,080
that focused on ourselves
as individuals - psychology.

530
00:44:34,440 --> 00:44:39,360
Psychology, as the name implies,
originally started out as

531
00:44:39,360 --> 00:44:42,080
the study of the psyche, or mind.

532
00:44:42,080 --> 00:44:45,120
The idea was, you could look
into yourself, introspect,

533
00:44:45,120 --> 00:44:47,200
and learn about human nature
that way.

534
00:44:47,200 --> 00:44:51,440
However, here in America, a small
group of psychologists soon decided

535
00:44:51,440 --> 00:44:54,520
that was nowhere near
rigorous or vigorous enough.

536
00:44:54,520 --> 00:44:59,400
They wanted to turn psychology
into a science, so they decided to

537
00:44:59,400 --> 00:45:04,600
focus on something they really could
measure and manipulate - behaviour.

538
00:45:11,880 --> 00:45:14,840
This approach, called behaviourism,

539
00:45:14,840 --> 00:45:17,520
was transformed
into a systematic science

540
00:45:17,520 --> 00:45:22,040
by one of the 20th century's
most controversial pioneers.

541
00:45:23,080 --> 00:45:25,960
His name was BF Skinner.

542
00:45:28,080 --> 00:45:30,760
Skinner was convinced
that our behaviour

543
00:45:30,760 --> 00:45:33,000
is the product of our environment,

544
00:45:33,000 --> 00:45:35,160
learnt from our experiences.

545
00:45:40,120 --> 00:45:43,320
Since Skinner thought that
environment was all-important,

546
00:45:43,320 --> 00:45:47,320
I thought it would be quite
interesting to have a look at
where he worked.

547
00:45:47,320 --> 00:45:50,120
This is his study.
Isn't it wonderful?

548
00:45:52,800 --> 00:45:58,720
This is completely unchanged from
when he died, over 20 years ago.

549
00:45:58,720 --> 00:46:02,240
He liked music,
so he had this adapted

550
00:46:02,240 --> 00:46:05,320
so that he could just pull that,

551
00:46:05,320 --> 00:46:08,600
and play his music.

552
00:46:09,960 --> 00:46:13,880
This is a man who likes to
tinker and adjust things.

553
00:46:15,360 --> 00:46:18,480
This is the bed
in which he used to sleep.

554
00:46:18,480 --> 00:46:22,120
It is absolutely filled
with his paraphernalia.

555
00:46:26,600 --> 00:46:28,440
It was his passion for gadgets,

556
00:46:28,440 --> 00:46:31,080
for things that he could
adapt and change,

557
00:46:31,080 --> 00:46:33,760
that led him to
his greatest invention,

558
00:46:33,760 --> 00:46:36,840
a device which is as iconic
to behaviourists

559
00:46:36,840 --> 00:46:39,560
as the telescope is to astronomers -

560
00:46:39,560 --> 00:46:43,760
the operant conditioning chamber,
or Skinner's box.

561
00:46:45,960 --> 00:46:50,560
Skinner's experiments
would reveal something surprising,

562
00:46:50,560 --> 00:46:55,080
and very disturbing,
about the human condition.

563
00:46:57,880 --> 00:47:01,440
This is an operant chamber.
Otherwise known as a Skinner box.

564
00:47:01,440 --> 00:47:03,880
It's a Skinner box.
Many people in my field...

565
00:47:03,880 --> 00:47:07,720
'Dr Robert Allan uses similar
methods to those Skinner used.'

566
00:47:07,720 --> 00:47:10,240
Here's an area
where the pigeon stands.

567
00:47:10,240 --> 00:47:11,840
Their response keys...

568
00:47:11,840 --> 00:47:14,400
'The pigeon has to
peck on these buttons.

569
00:47:14,400 --> 00:47:18,160
'If it pecks them in the right
order, it gets a reward.'

570
00:47:18,160 --> 00:47:21,600
So what are you going to do
to impress me with the pigeon today?

571
00:47:21,600 --> 00:47:24,720
I'll show you. Let's go get a pigeon.

572
00:47:24,720 --> 00:47:26,800
Who's this?

573
00:47:26,800 --> 00:47:29,040
This is G21.

574
00:47:29,040 --> 00:47:32,920
G21? I don't think of pigeons
as being smart, I must admit.

575
00:47:32,920 --> 00:47:36,560
They're very smart. Is he going to
demonstrate just how smart? Indeed.

576
00:47:36,560 --> 00:47:39,400
OK. In you go, G21. OK.

577
00:47:40,680 --> 00:47:44,320
Ooh. Is he hungry? It looks like!

578
00:47:46,640 --> 00:47:50,320
'The pigeon has to work out
whether the centre light

579
00:47:50,320 --> 00:47:52,720
'shines red or green for longest.

580
00:47:52,720 --> 00:47:56,640
'If it's green, it has to peck
the button on the right.'

581
00:47:56,640 --> 00:47:57,800
Oh, he's smart.

582
00:47:57,800 --> 00:48:00,640
Long green means go right.

583
00:48:00,640 --> 00:48:02,520
OK. So will he go right?

584
00:48:02,520 --> 00:48:05,600
Yes, he will. You're confident
in your bird, aren't you?

585
00:48:05,600 --> 00:48:08,840
I am very confident.
Ah! Very good. There you go.

586
00:48:08,840 --> 00:48:12,440
If it was red that was longest,
he has to go the other way.

587
00:48:12,440 --> 00:48:14,080
Now he has to go left.

588
00:48:14,080 --> 00:48:15,840
OK. Watch.

589
00:48:15,840 --> 00:48:18,960
Yes, he's done it.
He's very good, I have to say.

590
00:48:18,960 --> 00:48:20,840
I'm good at predicting behaviour.

591
00:48:20,840 --> 00:48:24,280
Well done, G21. Go, boy, go.

592
00:48:24,280 --> 00:48:30,280
'What these experiments showed
was how easily behaviour
could be learned, even manipulated.'

593
00:48:36,520 --> 00:48:40,280
'I was about to see how
quickly this can happen.'

594
00:48:40,280 --> 00:48:44,640
We are going to shape
the turning response

595
00:48:44,640 --> 00:48:49,920
by delivering reinforcers
for his approximate behaviour.

596
00:48:49,920 --> 00:48:55,600
You're going to make him sort
of turn in a circle, are you?
That's correct. That's better said!

597
00:48:56,640 --> 00:48:59,320
'Each time the pigeon turns left,

598
00:48:59,320 --> 00:49:03,560
'Dr Allan delivers food
to reinforce that behaviour,

599
00:49:03,560 --> 00:49:06,360
'until after just 20 minutes,

600
00:49:06,360 --> 00:49:09,320
'he has the pigeon
dancing round in circles.'

601
00:49:12,480 --> 00:49:16,360
'Pigeons and birdseed
may not look controversial,

602
00:49:16,360 --> 00:49:18,720
'but what was so shocking
at the time

603
00:49:18,720 --> 00:49:22,280
'was that Skinner applied
his ideas to human behaviour.'

604
00:49:24,960 --> 00:49:29,120
What Skinner was saying is that
we are in many ways like pigeons -

605
00:49:29,120 --> 00:49:33,720
that we are the product of
the numerous interactions
we have with our environment,

606
00:49:33,720 --> 00:49:37,360
whether it's falling in love,
the job, the friends you make,

607
00:49:37,360 --> 00:49:40,360
all these things which appear to be
decisions are actually

608
00:49:40,360 --> 00:49:43,440
the product of things that
have happened to us in the past.

609
00:49:43,440 --> 00:49:47,040
We can no more exercise free will
than this pigeon

610
00:49:47,040 --> 00:49:50,920
can decide whether to peck,
or indeed, turn in a circle.

611
00:49:55,600 --> 00:50:01,320
Skinner was convinced his discovery
could be used to benefit mankind.

612
00:50:05,280 --> 00:50:11,280
We could change people's
behaviour for the better
by changing their environment.

613
00:50:13,720 --> 00:50:18,800
But in the context of the Cold War,
the ability to control behaviour

614
00:50:18,800 --> 00:50:22,680
left some people fearful
it could be misused,

615
00:50:22,680 --> 00:50:27,000
because in Skinner's view, free will
was nothing but an illusion.

616
00:50:32,120 --> 00:50:37,160
Now, most of us believe
that being able to make choices
is an important part of being human,

617
00:50:37,160 --> 00:50:40,120
but here was Skinner saying that
that was an illusion,

618
00:50:40,120 --> 00:50:43,440
that actually it was a piece of
pre-scientific nonsense,

619
00:50:43,440 --> 00:50:47,040
akin to believing in
a flat Earth or demonic possession.

620
00:50:47,040 --> 00:50:53,600
You can imagine how popular that
message was in the land of the free
and the rugged individual.

621
00:50:56,440 --> 00:51:00,160
Behaviourism
was soon joined by other approaches,

622
00:51:00,160 --> 00:51:02,400
through the 1960s and beyond.

623
00:51:04,040 --> 00:51:08,120
There were new drugs, therapies,
personality tests,

624
00:51:08,120 --> 00:51:12,560
new ways to measure our thoughts,
memories and emotions.

625
00:51:14,800 --> 00:51:18,080
Psychology has grown into
a vast science,

626
00:51:18,080 --> 00:51:22,480
as diverse and multi-faceted
as we are.

627
00:51:29,960 --> 00:51:32,000
So, who are we?

628
00:51:33,720 --> 00:51:38,160
Well, we are the product of
our genes and our environment.

629
00:51:45,960 --> 00:51:49,120
Billions of neurochemical reactions

630
00:51:49,120 --> 00:51:52,640
firing every single second
of our lives.

631
00:51:55,440 --> 00:51:59,120
In us, reason and emotion
are frequently at war.

632
00:52:03,440 --> 00:52:07,560
Thoughts, passions,
memories and behaviour

633
00:52:07,560 --> 00:52:10,760
emerge unbidden out of the depths.

634
00:52:10,760 --> 00:52:13,600
Brain scans reveal
many parts of the brain

635
00:52:13,600 --> 00:52:16,640
operating outside
our conscious awareness.

636
00:52:27,240 --> 00:52:31,320
We are the product of
numerous daily interactions,

637
00:52:33,760 --> 00:52:39,200
and the quest to understand
the essence of who we are

638
00:52:39,200 --> 00:52:43,920
has revealed something fascinating
going on inside our heads,

639
00:52:43,920 --> 00:52:46,560
something none of us
are ever aware of.

640
00:52:48,840 --> 00:52:54,120
I can show you what I mean
with a famous visual illusion.

641
00:52:57,560 --> 00:52:59,800
HE LAUGHS

642
00:52:59,800 --> 00:53:02,160
'It's called the Ames room.'

643
00:53:02,160 --> 00:53:05,720
That is so bizarre!

644
00:53:05,720 --> 00:53:07,760
Clearly, what I'm seeing is,

645
00:53:07,760 --> 00:53:11,280
I'm seeing a very, very tall
person over there

646
00:53:11,280 --> 00:53:14,840
and a short person over there,
and when they swap over,

647
00:53:14,840 --> 00:53:18,040
there's a moment
when my brain just goes clunk.

648
00:53:19,240 --> 00:53:25,800
I absolutely know this is an
illusion, but my brain just won't
let me see through the illusion.

649
00:53:29,320 --> 00:53:30,880
So how's it done?

650
00:53:30,880 --> 00:53:33,520
Well, if you come over this way,

651
00:53:33,520 --> 00:53:35,560
it's really obvious.

652
00:53:35,560 --> 00:53:39,240
Hi, there. Thank you.

653
00:53:39,240 --> 00:53:41,960
OK, so essentially,

654
00:53:41,960 --> 00:53:44,960
the room really dips downhill.
Lots of space above my head.

655
00:53:44,960 --> 00:53:47,880
There is a sharply sloping floor.

656
00:53:47,880 --> 00:53:53,200
As I march up,
the room begins to narrow until
I'm really crunched into the corner.

657
00:53:53,200 --> 00:53:56,440
There's very little space between
the ground and the top here,

658
00:53:56,440 --> 00:53:59,600
and that's how
the illusion is created.

659
00:53:59,600 --> 00:54:04,320
Essentially,
the room is a trapezoid.

660
00:54:06,200 --> 00:54:09,240
The Ames room shows us
something very important

661
00:54:09,240 --> 00:54:11,240
about how the brain is working.

662
00:54:12,800 --> 00:54:17,680
There's part of my brain
which knows the rules of a room.

663
00:54:17,680 --> 00:54:20,600
It has assumptions,
models built in there,

664
00:54:20,600 --> 00:54:23,520
and it knows, based on experience,

665
00:54:23,520 --> 00:54:27,840
that normally in rooms, the ceiling
and the floor is parallel,

666
00:54:27,840 --> 00:54:30,800
and that the walls
are at a right angle.

667
00:54:30,800 --> 00:54:33,240
From one particular viewpoint,

668
00:54:33,240 --> 00:54:36,880
the room looks like
it fits that mental model,

669
00:54:36,880 --> 00:54:41,640
and the brain has such a powerful
belief that this quirky-shaped room

670
00:54:41,640 --> 00:54:45,440
is normal that people appear
to have changed size.

671
00:54:48,040 --> 00:54:53,040
This illusion
reveals something fundamental
about how the brain works.

672
00:54:54,600 --> 00:54:59,240
Our perception of reality is not
just based on what is out there,

673
00:54:59,240 --> 00:55:02,080
but it is also
partially constructed.

674
00:55:02,080 --> 00:55:05,080
We have these models
running in our head,

675
00:55:05,080 --> 00:55:09,720
and they are constantly being tested
against the evidence of our senses.

676
00:55:17,280 --> 00:55:22,960
This process of building models
in our heads is happening
from the moment we are born.

677
00:55:24,800 --> 00:55:28,720
This child is using her senses
to find out about the world.

678
00:55:31,040 --> 00:55:34,880
Is that person in the mirror
another baby, or is it me?

679
00:55:36,440 --> 00:55:40,360
Why does that thing make a noise
when I shake it?

680
00:55:40,360 --> 00:55:43,880
What she's doing
is constantly learning

681
00:55:43,880 --> 00:55:46,880
by testing everything around her.

682
00:55:48,520 --> 00:55:51,200
Thousands of little experiments
like these

683
00:55:51,200 --> 00:55:53,800
will create
her unconscious assumptions.

684
00:55:56,040 --> 00:56:01,160
They'll build the models
that shape her view of the world.

685
00:56:01,160 --> 00:56:04,960
That's how she will be able to
make her way through life.

686
00:56:10,240 --> 00:56:14,720
It is very charming when you think
that in a way, what she's doing now

687
00:56:14,720 --> 00:56:17,480
is acting rather like
a mini-scientist.

688
00:56:17,480 --> 00:56:22,040
She's investigating the world,
she's forming her theories,

689
00:56:22,040 --> 00:56:26,720
her hypotheses, and she's
testing them against reality.

690
00:56:26,720 --> 00:56:30,880
'And that, in a sense, is what
science is, and it's going on

691
00:56:30,880 --> 00:56:35,480
'inside each and every one of us
from the moment we're born.'

692
00:56:35,480 --> 00:56:37,560
Is that right, Chloe? Is that right?

693
00:56:37,560 --> 00:56:39,080
It is.

694
00:56:44,400 --> 00:56:51,320
In this programme,
we've seen that humans are
creatures of both rational thought,

695
00:56:51,320 --> 00:56:53,800
and emotional turmoil.

696
00:56:55,920 --> 00:56:59,040
And in this series,
I've shown how science too

697
00:56:59,040 --> 00:57:01,920
has been shaped by
reason and emotion,

698
00:57:01,920 --> 00:57:07,320
as well as by the tumult of
the world in which it operates.

699
00:57:09,720 --> 00:57:13,840
Its intellectual achievements
have transformed our lives.

700
00:57:21,600 --> 00:57:25,200
But it hasn't been straightforward.

701
00:57:25,200 --> 00:57:28,360
The story of science is a messy one,

702
00:57:28,360 --> 00:57:33,240
wrapped up in politics,
belief, money and rivalry,

703
00:57:33,240 --> 00:57:36,080
proof forever shaped
by power and passion.

704
00:57:40,320 --> 00:57:44,160
Science is a very human activity,

705
00:57:44,160 --> 00:57:48,800
something we unconsciously do
every day -

706
00:57:48,800 --> 00:57:54,040
observing the world, building
mental models, and testing them.

707
00:57:55,560 --> 00:57:59,200
But it's when we deliberately
started using the scientific method

708
00:57:59,200 --> 00:58:03,240
that we went way beyond
our individual capabilities.

709
00:58:05,760 --> 00:58:09,800
I think science is
the greatest collective endeavour

710
00:58:09,800 --> 00:58:12,440
that mankind has ever undertaken.

711
00:58:18,160 --> 00:58:21,040
Over the last few thousand years,

712
00:58:21,040 --> 00:58:23,440
the human brain
has not changed at all.

713
00:58:23,440 --> 00:58:25,720
Evolution does not go that fast.

714
00:58:25,720 --> 00:58:29,720
But what has changed
is our understanding of the world.

715
00:58:29,720 --> 00:58:33,240
We don't have to rely simply on
the wisdom of our own brains.

716
00:58:33,240 --> 00:58:34,760
SHE GURGLES

717
00:58:34,760 --> 00:58:37,440
We have language,
we have literature,

718
00:58:37,440 --> 00:58:41,360
and now we have computers,
and that links us all together.

719
00:58:41,360 --> 00:58:43,280
That gives us, if you like,

720
00:58:43,280 --> 00:58:46,680
the wisdom of
all those who have gone before.

721
00:58:56,880 --> 00:59:00,400
Subtitles by Red Bee Media Ltd

722
00:59:00,400 --> 00:59:03,920
E-mail subtitling@bbc.co.uk