I don't mind telling you, I'm scared to death.
This is the Reid polygraph, a lie detector.
200,000 persons have staked their futures,
many of them their lives, on this machine.
But today,
there is a new way of detecting lies.
For the first time in nearly a century, it could prove to be
a more accurate alternative to the polygraph.
Is your name Edward Cummings?
Yes.
Deception is not always
a matter of life and death.
We all tell lies.
We see when people say, "I'm on my way."
In fact, you know they're not, but it's a little lie.
But some deceptive behavior
can have a more sinister intent.
I washed some knives
that I had sharpened the night before.
I think.
New research into deception
is rewriting the rules of lie detection
and it is all down to simply measuring
how the whole body moves.
We were watching the water levels.
Yeah, the national water levels for that area
or local water levels of the rivers.
The research offers the extraordinary promise
of also identifying criminal or terrorist behavior.
There's the potential that you could have
a large number of these rigs in large areas,
looking at people as they come through passport control
and potentially protect a lot of people
and save lots of lives.
But as the new technologies
promise to make the world safer,
it is in the online world where the human instinct
for deception has found new freedoms.
There's something very interesting.
You see, in online dating, because everybody lies,
people feel it's okay to lie a little bit
just to be like everybody else.
And then they meet for coffee
and they set themself up for disappointment.
But can science really separate
the truth from the lies?
I'm able now to tell you, based on those movements,
which one of the stories is true and which one is a lie.
Does the new lie detector really work?
We're going to find out.
My lie was...
The truth was...
(serious piano music)
(machine beeping)
At Cambridge University,
Sophie van der Zee is the scientist leading research
for the ultimate lie detector.
So, based on the literature, we actually don't really know
if people move more or less when they're lying,
because there's very mixed results out there.
And that means that we thought,
"Let's put someone in a full-body motion suit
"and see what happens.
"Let's sort of end this discussion once and for all
"if people are moving more or less when they're lying."
To make an accurate lie detector is not easy.
The scientific basis for the polygraph
has always been disputed.
The conscious act of lying
creates an emotional disturbance.
Its accuracy is more
the stuff of Hollywood myth.
Its critics claim a success rate of just 70%.
But could something as simple as the way a person moves
reveal their innocence or their guilt?
17 different inertial sensors that are placed on the body,
literally from head to toe.
And what they do is they sort of create a 3-D image
of the person that is wearing the suit
and are sending to a laptop
who then creates sort of a stick figure
of all the movements that someone is making.
Sophie's work is causing a bit of a stir
in the world of deception research.
Today, she is presenting her findings
to the world's very first Decepticon conference,
hosted by Cambridge University.
Almost everybody who's into deception,
not everybody, but so many are here.
So, this is a great chance to get us all together,
because we're from a variety
of different academic disciplines
and a lotta non-academic folks here too.
So, it'll be a good chance to find out
what everybody else is doing.
So, if you're in an experiment,
they ask you to pick a side: top or bottom.
Also presenting his research
is behavioral economist and TED star Dan Ariely.
In simple experiments, he looked at how people cheat
and he noted that they usually start
by cheating just a little.
I think that when people start the path of behaving badly,
at that moment, if you connected them to a lie detector,
there would be no reaction.
At that moment, they would think that they're actually okay.
A little bit of self-deception,
a little of wishful blindness, a little--
What Dan has identified in all of us
is something he calls the fudge factor.
So, here's what we basically find.
What we find is that people are trying to balance
two motives at the same time.
We try to look in the mirror and feel good about ourselves
and feel that we're honest, wonderful people.
At the same time, we try to cheat a little bit
and benefit from that.
And you could say, "How could you do both?
"You could choose one or the other."
It turns out we can do both.
How?
As long as we can convince ourselves
that we're actually not doing something bad,
and this is what we call the fudge factor.
If we all think it's okay
to cheat just a little bit,
then where better to properly use our fudge factor
than when we are online?
One of the cool things about technology
is it can take the psychological principles of deception
and they apply online really nicely.
So, we can take people like Dan Ariely's work
that suggests that everybody does these small little lies.
Well, we can look at online dating.
Men say they're about nine-tenths of an inch taller,
a strong rounding-up.
Men care a lot about women's weight,
and therefore women lie about weight to a higher degree.
On their resumes, they'll lie a little bit
about how long they worked at a place,
but they won't make up jobs that they never were at.
This is where Sophie's research comes in.
She believes that you give your lies away,
not by what you say but by how you move.
First, she asks for two stories.
One will be the truth, the other a lie.
Will you be able to spot the lie?
I am going to ask you twice what you did yesterday morning
between 8:00 and 12am.
The idea is that you'll sort of
answer these questions truthfully once and lie to me once
about what you were doing yesterday morning.
So, at noon, I, (pausing)
around then I looked at the clock on my computer
and realized that I had to go
while I was doing my taxes, my tax receipts.
The table was full of receipts.
I'm going to ask you two sets of questions
about your last holiday.
So, I went to Curacao for my mom's birthday this summer.
So, my mom turned 50 this year
and, yeah, we celebrated her 50th birthday there
and we were there for a week with the whole family.
A lotta the times, I'll ask people,
"Where do you think lies happen the most,
"on the internet or face-to-face?"
And most people, well, everybody says,
"Oh, on the internet, for sure."
But actually, a lot of our studies suggest
that if I'm talking to somebody I know,
so not a Nigerian prince, not a scam artist,
but I'm talking to my friend, my boss, my wife,
online communication can often be more honest.
And the reason for that is the record that's left behind.
I had breakfast.
I washed some knives that I had sharpened the night before.
I think.
Did you get her a gift?
Well, we bought her a cake.
So, there's a special cake on the islands,
like a local cake.
It's made of cashew nuts.
So, we ordered the cake in advance
and we bought her this cake
and she was very happy with that.
So, if I ask you,
"How do you know when somebody's lying to you,"
number one answer worldwide:
liars won't look you in the eye.
If you ask people a little differently,
"Think about the last time you found out
"somebody was lying to you, how'd you find out,"
it's because of some kind of evidence, right?
Your friend told you, "Oh, they didn't say that,"
they actually only would slip up later.
So, most lies are detected well after the fact
on the basis of evidence.
Having told their first story,
the interviewees now tell their second.
I met a friend.
My last holiday was in the south of France.
He said, "Do you want to meet me for breakfast in town?"
And while we were there, we were flooded by water,
and this was quite serious.
People have always liked
telling us about their holidays.
But now, more and more,
we are using their online travel reviews
when choosing where to go, where to stay.
But should we trust them?
And so, what we've done is looked at
the language of fake reviews and truthful reviews
and we can create algorithms that'll tell us
this person's been at this hotel and this is a legit review
or no they haven't and it's totally fake.
So, one of the ways we can tell
if somebody's been in a hotel room, for example,
is the way they use small little words like "I".
So, if they talk about themselves a lot
and who they were with, it's probably a lie.
Whereas a truth-teller, they went in there,
their body experienced the space,
they know whether the bathroom is small or large,
they know where the restaurant is relative to the lobby,
and they know if shopping's nearby.
And so, you see a lotta spatial words
like near, on, small, big,
whereas a liar is just making up a story
and it doesn't include those kinda words.
But for Fernando and Evian,
the big question is can Sophie's algorithms
tell which of their stories were the lies?
Here you can see the stick figure.
The stick figure is actually Evian
and how she was moving during the interview
when she was talking about her holiday in France.
At the moment, the top is quite red.
But the more she starts moving, the more red it becomes.
So, we've been looking at that,
both as a full-body measure, which you can see down here,
so that's sort of an aggregated measure
of how much Evian was moving over her entire body,
and then we also look at it per body part.
With the data collected,
it was sent to Sophie's colleague, Ronald Poppe,
in Utrecht University for analysis.
Was he able to separate the truths
from the lies? Ronald, are you there?
Hi, Sophie.
Yes, I had a look at the motion capture files
for each person.
I'm able now to tell you, based on those movements,
which one of the stories is true and which one is a lie.
My lie was--
But after the analysis,
we know that he was lying in his second story,
and I believe that was a story
about going to meet a friend for breakfast.
That I went for breakfast with that friend
and then had a voiceover.
So, that means that the truth was--
I did do my taxes.
Evian moves way less,
but we believe that in her first story,
the one where she went on holiday with her mother
to celebrate her birthday, she was lying.
It was not my mom's birthday.
She did not turn 50 this summer.
And therefore, the truth was that she went to France,
where she had quite a flooded vacation.
In controlled experiments,
this analysis of body motion had a success rate
of around 82% in sorting the lies from the truth.
Promising to be more accurate than the polygraph,
it could be the first new lie detector in over 80 years.
But more remarkably, used remotely,
it might one day help identify
criminal or terrorist behavior.
But if you ever wanna apply it in practice,
you need step away from those suits
because you can't really ask people in an airport
to put on a suit, as you want to measure movement remotely.
So, that's what we've been working on this summer.
And this can be used as well, for example,
for border control screening like Judee Burgoon in Arizona.
We've been doing a lot of research
looking for a lot of different sensors
that might be helpful for detecting deception automatically,
and especially non-contact ones
so that you can do it remotely,
you don't have to hook anybody up to wires or anything.
This is a Google Tango, which, as you can see,
it's a tablet computer.
But the sensors mounted across the top here
are the same sensors
that we were using in the lie detection rig.
These are the infrared emitters and infrared camera
that we use to determine the depth in the scene
and then detect motion.
There's the potential that you could have
a large number of these rigs in large areas,
looking at people as they come through passport control.
Some of the things we're learning,
some of the technologies that are being developed
can all help us in the battle against the unpredictable
and the bad actors that are out there.
And potentially protect a lot of people
and save lots of lives.
(tape rewinding)