Te l l i n g L i e s : C a n You
Read It In T heir Eyes?
C I
RC
Sour c e : D e Pa u l o, B. M . , L i n d s a y, J. J. , M a l o n e , B. E . , M u h l e n b r u c k , L . , C h a r l t o n , K . , &
Cooper, H. (2003). Psychological Bulletin, 129, 74-118.
Goals:
Te a c h t h e i m p o r t a n c e
of clearly defining
t e r m s.
Te a c h t h e m e t h o d o f
proof by disproof.
Basic Idea:
How can you tell if
someone is lying?
Deception is often
associated with
physical cues that may
r e v e a l a l i e . B u t i t ’s
not as easy as it might
seem to correctly spot
t h e h i n t s.
T h i n k & Wr i t e # 1
What is a lie?
H a v e s t u d e n t s w r i t e w h a t t h e y t h i n k a b o u t l i e s.
What is a lie? How can you tell?
Gain Attention/Interest:
I doubt there are many people (other than perhaps
G e o r g e Wa s h i n g t o n ) w h o n e v e r t e l l l i e s. L i e s d o n’t
have to be big; they can be little ones like, “that
l o o k s r e a l l y n i c e o n y o u ” o r “ y o u r h a i r d o e s n’t l o o k
t h a t b a d ” o r “ y o u r b u t t i s n’t t o o f a t .” S o m e
researchers have asked people to keep a diar y of
t h e i r l i e s. T h e y f o u n d t h a t p e o p l e a v e r a g e a b o u t o n e
o r t wo l i e s e v e r y d a y. Q u i t e f r e q u e n t l y p e o p l e g e t
a w ay w i t h l i e s a n d n o o n e i s e v e r t h e w i s e r. B u t
could they be? Are some people better at telling lies
than others? Is there some secret way to always
k n o w i f s o m e o n e i s n’t t e l l i n g t h e t r u t h ? A r e t h e r e
tricks to telling when someone is lying?
C u r r e n t l y, t h e r e a r e s e v e r a l m a c h i n e s t h a t c a n a s s i s t
u s i n g u e s s i n g w h e t h e r o r n o t s o m e o n e i s l y i n g.
These machines do things like keep track of heart
r a t e , b r e a t h i n g r a t e , h o w m u c h a p e r s o n s w e a t s, a n d
e ve n b r a i n a c t i v i t y. H o w e ve r , t o d a y w e a r e g o i n g t o
l i m i t o u r d i s c u s s i o n t oAtchte i tvhii nt y
gs humans can do
w i t h o u t t h e a i d o f t e c h n o l o g y t o d e t e c t l i e s.
www.circ.cornell.edu
C o p y r i g h t © 2 0 0 5 M a t t h e w C . M a k e l & We n d y M . W i l l i a m s . P r i n c i p a l I n v e s t i g a t o r : We n d y M . W i l l i a m s .
C o n t e n t : M a t t h e w C . M a k e l & We n d y M . W i l l i a m s . L a y o u t & D e s i g n : P a u l B. P a p i e r n o.
Ask: What is Science?
O b v i o u s l y, w e c a n’t s t u d y l i e s b y s y s t e m a t i c a l l y h a v i n g
e ve r y p e r s o n w e m e e t t e l l u s a l i e , a n d t h e n t e l l u s w h a t
t h e y w e r e l y i n g a b o u t . S o, h o w c a n w e l e a r n t h e t r u t h
about lies? Through science.
1
Ask:
What
is
Science?
S c i e n c e a n s w e r s q u e s t i o n s o r s o l v e s p r o b l e m s. S c i e n c e
can reveal the facts and the trends showing how people
b e h a v e i n d i f f e r e n t s i t u a t i o n s. S c i e n c e wo r k s t h r o u g h
a process called proof by disproof. Scientists create a
hypothesis (a guess) and then tr y
PROOF BY DISPROOF
different ways to prove their
h y p o t h e s i s w r o n g. I f a l l o t h e r
Nonscientists seek support
by gaining proof for their
possible answers are shown to
b e l i e f s o r h u n c h e s.
h a ve f l a w s w h a t e v e r i s l e f t i s t h e b e s t a n s w e r.
Scientists seek to disprove
Scientists support their answer by eliminating the
t h e i r b e l i e f s a n d h u n c h e s.
i n c o r r e c t o n e s. T h i s i s d i f f e r e n t t h a n h o w a
If they fail to disprove an
idea, then they believe they
nonscientist typically approaches a problem.
have some proof it might
Nonscientists usually just check to see if their guess
be true.
s e e m s r i g h t , a n d d o n’t w o r r y a b o u t o t h e r p o s s i b l e
a n s w e r s.
2
Define
the
Problem:
See
Many
Sides.
Define the Problem: See Many Sides
Before going further, we need to do something that
a l l s c i e n t i s t s d o, y e t m a y s e e m s t r a n g e t o y o u . We
need to define the ter ms with which we are working;
we need to define a lie. Defining ter ms is essential
because without a definition, people could confuse
what we mean with what they think we mean. This
process is called developing a working definition.
Without a definition ever yone ag rees upon, people
might think you mean something other than what
y o u i n t e n d . Fo r e x a m p l e , t h i n k o f t h e wo r d “ b i g.”
W h a t i s b i g ? I t d e p e n d s. W h e n y o u a r e r e f e r r i n g t o a
b i g s h i p, d o y o u u s e t h e s a m e r e f e r e n c e p o i n t a s
when you refer to a big pizza?
S o, i f w e ’r e g o i n g t o b e a b l e t o i n v e s t i g a t e l y i n g
s c i e n t i f i c a l l y, w e n e e d t o c o m e u p w i t h a wo r k i n g
definition.
T h i n k & Wr i t e # 2 a
Developing a working definition for a lie.
Have students write a working definition for a lie.
Does it differ from their first definition? How?
Here is a vignette that exemplifies why a clear definition of a lie is
important.
Vignette
I t ’s Fr i d a y n i g h t a n d Ty l e r i s g e t t i n g r e a d y t o g o o u t t o a p a r t y t h a t h e d o e s n ’t
want his parents to know about. Rather than lie directly to them, he tells his
l i t t l e s i s t e r G i n a t h a t h e i s g o i n g t o a f r i e n d ’s h o u s e t o w a t c h a m o v i e . G i n a
b e l i e v e s h i m a n d t h e n t e l l s t h e i r p a r e n t s t h a t T y l e r h a s g o n e t o a f r i e n d ’s h o u s e .
D i d Ty l e r l i e t o G i n a ? To h i s p a r e n t s ? D i d G i n a l i e t o h e r p a r e n t s ? W i t h
whom should the parents be upset?
M a n y s c i e n t i s t s d e f i n e a l i e a s “ a d e l i b e r a t e a t t e m p t t o m i s l e a d o t h e r s.” A
n o n - t r u t h t h a t i s m i s t a k e n l y o r u n k n o w i n g l y c o m m u n i c a t e d wo u l d n o t b e
c o n s i d e r e d a l i e . U s i n g t h i s d e f i n i t i o n , G i n a i s o f f t h e h o o k , b u t Ty l e r m a y
n o t b e s o l u c k y.
O b v i o u s l y, p r e t t y m u c h e v e r yo n e w a n t s t o k n o w w h e t h e r o r n o t s o m e o n e i s
lying to them, but what particular groups of people are interested in lies as
p a r t o f t h e i r d a i l y w o r k a n d p e r s o n a l l i v e s ? ( S o l i c i t a n s w e r s. )
l i c e o f f i c e r s. W h e n t h e y a r e i n ve s t i g a t i n g c r i m e s a n d q u e s t i o n i n g
· Po
s u s p e c t s, t h e y n e e d t o b e a b l e t o d i s t i n g u i s h t h e t r u t h f r o m l i e s.
· Cn or itmt ion aglos. t oI fj a ti lh. e y ’ v e b e e n c a u g h t , t h e y l i k e l y w a n t t o f i g u r e o u t a w a y
· Lt oa wf iynedr s,t hJue dt gr ue s,t h .a n d J u r i e s.
The goal of our criminal justice system is
· Te a c h e r s. T h e y w a n t t o k n o w w h e n s t u d e n t s a r e l y i n g t o t h e m .
· Paa b lree nttos /cSopmomu suensi/cCa thei lwd ri tehn .e aIcth i os tihme pr oarntda nkt nfoowr fi fa mt hi ley tmr uetmh biesr sb etion gb e
told.
· Bn eoesds etso aknndoewmwp lhooyme e s.t h e yPecoapnl eb ewl hi eov ed.e p e n d o n o n e a n o t h e r a t wo r k
Distinguish Fact From Opinion:
Learn What Constitutes Scientific Evidence
T h i n k & Wr i t e # 2 b
Find the physical facts.
Are there any people you know who sometimes do
things that make you think they are lying? What
are some typical “giveaways” of a liar?
3
Fact Versus
Opinion:
What
Constitutes
Evidence?
How many of these “giveaways” do you think are
s p e c i f i c t o a n i n d i v i d u a l , o r g r o u p o f i n d i v i d u a l s,
or to a specific situation? How many do you think
apply universally to (nearly) ever yone? These are
the differences that distinguish fact from opinion.
A fact is something a police officer could use to
analyze the response of anyone she/he is
q u e s t i o n i n g. D o a l l p e o p l e s t u m b l e o ve r t h e i r
words if and only if they are lying? If this were a
fact, the job of a police interrogator would be
m u c h e a s i e r. H o w e ve r , i t i s n o t a f a c t . M a y b e t h e
person is just ver y ner vous or dr unk! It is the job
o f a s c i e n t i s t t o d i s c o v e r t h e f a c t s, a n d n o t j u s t t o
g o w i t h a g u t f e e l i n g.
Activity
H a v e t h e c l a s s f o r m g r o u p s o f 4 - 5 s t u d e n t s. H a v e e a c h s t u d e n t
think of three facts about herself or himself that others in the
g r o u p p r o b a b l y wo u l d n’t k n o w, w i t h 2 b e i n g t r u t h f u l a n d 1 b e i n g a
l i e . H a v e e a c h p e r s o n s h a r e a l l t h r e e s t a t e m e n t s w i t h t h e g r o u p,
and have the group vote on which they believe to be the lie.
Discuss as a class whether there were give-aways that revealed
w h e n p e o p l e t o l d t h e i r l i e. We r e t h e r e s i m i l a r i t i e s a m o n g t h o s e
who lied successfully? How about those who were caught?
4
Weigh Evidence and Make Decisions
It is important to note that lies are not always more
c o m p l e x t h a n t h e t r u t h . Re p l y i n g t o t h e q u e s t i o n ,
“How was your day?” with “Fine” is an example of a
p o t e n t i a l e a s y, s i m p l e l i e . S o m e t i m e s t h e t r u t h i s m o r e
complicated than a lie.
Weigh
Evidence
and
Make
Decisions.
So how do scientists distinguish a lie from the tr uth?
I n m a n y c a s e s, t h e y h a v e p e o p l e p a r t i c i p a t e i n
experiments and ask them to lie or to tell the tr uth.
Then, while watching them, scientists look for trends
i n b e h a v i o r. A n o n s c i e n t i s t m i g h t j u s t t r y o n e m e t h o d
on a few people. However, a scientist relies on a
m u l t i t u d e o f d i f f e r e n t m e t h o d s. T h e s e m e t h o d s c o u l d
include having people watch a video and judge whether
a person was lying, or having people cheat at a game, or simulate a job
inter view in which a person either tells the tr uth or lies—each used on
hundreds of different people—to decide. When reviewing the results they
h a v e f o u n d o v e r t h e y e a r s, s c i e n t i s t s h a ve f o u n d m a n y t e l l t a l e s i g n s o f l i e s.
P h y s i c a l s i g n s o f i n c r e a s e d m e n t a l e f f o r t a r e f r e q u e n t l y s i g n s o f l y i n g.
These physical changes can be things such as:
· s( spuecahk i ansg twh iet hw omrodrse “pu amu”s easn da n“du hi n”t)e r r u p t i o n s
· pupil dilation
· decreased blinking
· less eye contact
· pressing lips together more frequently
· becoming less involved in the conversation
· appearing ner vous
· seeming less cooperative
· being less likely to admit a lack of memor y or a mistake
Scientists have found that well-rehearsed lies can frequently appear “too
s m o o t h ” a n d w e l l - t h o u g h t - o u t . F r e q u e n t l y, l i a r s s t u m b l e o v e r w o r d s a n d
f o r g e t t h i n g s, o r n e e d t o c o r r e c t t h e m s e l v e s. Ty p i c a l l y, l i a r s p r o v i d e f e w e r
d e t a i l s a n d t a l k l e s s. A s t h e s t a k e s r i s e , s o d o t h e c u e s t o l i e s. W h e n t h e r e
is more pressure, there are more cues that may reveal a lie.
T h i n k & Wr i t e # 3
How about now?
Have students write about their thoughts now
that they have learned how scientists think about
l i e s.
Move From Science to Society
I n f o r m a t i o n a b o u t l i e s i s h e l p f u l t o e v e r yo n e , n o t j u s t p o l i c e o f f i c e r s,
j u d g e s, a n d — u n f o r t u n a t e l y, c r i m i n a l s ! S e e i n g s o m e o n e s t u m b l i n g o ve r h i s
words or not making eye contact does not guarantee that he is telling a lie.
When present, cues to lies simply sug gest that deception
may be present. They do not divulge the subject of
deception or whether the person simply talks like that all
t h e t i m e . A l s o, t e l l i n g t h e t r u t h i s o f t e n h a r d t o d o, a n d
any sign of effort should not be considered an alar m for a
l i e . S o m e t i m e s t h e t r u t h i s h a r d e r t o t e l l t h a n a l i e . Wo u l d
y o u e v e r t e l l y o u r g r a n d m o t h e r y o u d i d n’t l i k e t h e m e a l
she cooked for you? Or is it just easier to say that it was
delicious?
5
Move
From
Science
To
Society.
One witness in a trial may frequently pause, stutter, and
g i ve s h o r t a n s w e r s, w h e r e a s a n o t h e r w i t n e s s a r g u i n g t h e
opposite points may appear calm and comfortable. Which
one is the liar? Can you tell just by this description?
What if you knew that the witness who was calm and
comfortable was a lawyer accustomed to being in a court
room and speaking in front of large groups of people, but
the first witness was extremely shy and had never been in
a c o u r t r o o m ? Wo u l d t h i s i n f o r m a t i o n i n f l u e n c e y o u r t h o u g h t s ? J u d g e s,
j u r i e s, a n d l a w y e r s a r e f o r c e d t o m a k e d e c i s i o n s s u c h a s t h e s e e v e r y d a y.
Pe o p l e i n o t h e r c a r e e r s a l s o n e e d t o k n o w t h e s c i e n c e b e h i n d l i e s.
P o l i c e O f f i c e r. W h e n t h e y a r e i n ve s t i g a t i n g c r i m e s a n d q u e s t i o n i n g
s u s p e c t s, t h e y n e e d t o b e a b l e t o d i s t i n g u i s h t h e t r u t h f r o m l i e s. Po l i c e
officers typically do not have an official education requirement, but having
at least a high school diploma is typical, and usually some further education
( s u c h a s a n a s s o c i a t e ’s d e g r e e ) .
Criminal. If they’ve been caught, they likely want to figure out a way not
t o g o t o j a i l , a n d n o t t o g i v e a w a y t h e i r l i e s. T h e r e i s n o a g e o r e d u c a t i o n
r e q u i r e m e n t t o b e a c r i m i n a l . T h e y c o m e i n a l l s h a p e s a n d s i z e s, a n d w h i l e
t h e r e m a y b e s h o r t - t e r m g a i n s, t h e l o n g - t e r m p i c t u r e t y p i c a l l y l e a d s t o a
career change (such as jail).
Te a c h e r. Te a c h e r s w a n t t o k n o w w h e n s t u d e n t s a r e l y i n g t o t h e m .
Te a c h e r s a t t e n d f o u r - y e a r c o l l e g e s a n d o f t e n o b t a i n a m a s t e r ’s d e g r e e a s
well.
Revisit, Review, Reflect, and
Re-evaluate
The final word on lies and deceptive behavior has yet
to be spoken. As you have likely discovered, the topic
of lies is a tricky subject. Scientists are constantly
r e v i s i t i n g t h e p r o b l e m , r e v i e w i n g p a s t a n s w e r s, a n d
reflecting on how they can improve their methods of
t e s t i n g w h e t h e r o r n o t a p e r s o n i s l y i n g. R a t h e r t h a n
starting from scratch each time, scientists review the
work that has already been done in search of flaws and
areas that could be improved, and re-evaluate past
solutions to see if they still work.
6
Revisit,
Review,
Reflect,
and
Re-evaluate.
One example is the lie detector test, used widely
t h r o u g h o u t t h e U n i t e d S t a t e s. S c i e n t i s t s a r e r e v i s i t i n g t h e s c i e n c e b e h i n d
lie detection to tr y to make these machines harder to fool. Some criminals
h a v e b e e n k n o w n t o b e a b l e t o t r i c k t h e m a c h i n e s, a n d s o m e i n n o c e n t
people have been known to be identified falsely as having lied. The science
b e h i n d l i e d e t e c t i o n t e c h n o l o g i e s i s o n g o i n g a n d i m p r o v i n g.
T h i n k & Wr i t e # 4
What's next?
Based on what they know now, have students hypothesize about what fur ther
scientific studies might be done so that scientists can better understand lying
b e h a v i o r.
Po t e n t i a l i d e a s : D o p e o p l e b e c o m e b e t t e r w i t h p r a c t i c e ? Ar e s o m e p e o p l e b e t t e r
than others? What about people who know each other versus people who are
strangers?
Discussion Questions
1 . T h e a c t i v i t y i n vo l v i n g t e l l i n g t wo t r u t h s a n d a l i e w a s d o n e a f t e r w e
d i s c u s s e d h o w t h e r e c a n b e p h y s i c a l c u e s t o l i e s. Wo u l d i t h a v e m a d e a
difference if we had done the activity before this discussion? Why?
How could we check?
2. What are some ways in which the ability to analyze lying is important
that we have not discussed in class?
H o m e wo r k Q u e s t i o n s
1 . Re p e a t t h e “ 2 t r u t h s a n d 1 ” l i e e x e r c i s e w i t h a g r o u p o f p e o p l e w h o
know you. Does this make it harder to lie? Does it make it easier to
tell when someone is lying? What does this tell you about lying
behavior?
2. In this lesson, we discussed the definition of a lie in depth. Are all lies
the same? How can you define different kinds of lies? Lies could be
d i f f e r e n t i a t e d b y t h e i r s i g n i f i c a n c e t o t h e l i a r ( e . g. , a n i m p o r t a n t l i e
versus an unimportant lie). Lies could also be differentiated by
whether or not they were created on the spot or ahead of time.
Cor nell Institute for
Research on Children
January 3, 2005
Quiz Questions
Ve r s i o n A
1 . Tr u e o r f a l s e : S p e a k i n g w i t h m o r e p a u s e s a n d i n t e r r u p t i o n s i s a l w a y s a
g i v e a w a y t h a t t h e p e r s o n i s l y i n g.
2. Select one of the following groups of people and explain how and why
t h e y a r e i n t e r e s t e d i n l i e s a s a p a r t o f t h e i r d a i l y w o r k o r p e r s o n a l l i v e s.
Po l i c e o f f i c e r s
Criminals
Te a c h e r s
Pa rents
Children
3. Select the best example of a scientific working definition for a lie.
a . a d e l i b e r a t e a t t e m p t t o m i s l e a d o t h e r s.
b. n o t t e l l i n g t h e t r u t h .
c. something that is not a fact.
d. it depends on the situation.
Quiz Questions
Ve r s i o n B
1 . A c c o r d i n g t o t h e l e s s o n a b o u t t e l l i n g l i e s, w h i c h o f t h e f o l l o w i n g i s
NOT a physical sign that someone could be lying?
a. pupil dilation
b. m o r e e y e c o n t a c t
c. becoming less involved in the conversation
d.
a p p e a r i n g n e r vo u s
2 . A c c o r d i n g t o t h e l e s s o n a b o u t t e l l i n g l i e s, w h i c h o f t h e f o l l o w i n g i s
NOT a physical sign that someone could be lying?
a . s p e a k i n g m o r e q u i c k l y.
b. s e e m i n g l e s s c o o p e r a t i v e.
c. p r e s s i n g l i p s t o g e t h e r m o r e f r e q u e n t l y.
d. speaking with more pauses and inter r uptions (such as “um”).
3. Select the best example of a scientific working definition for a lie.
a . a d e l i b e r a t e a t t e m p t t o m i s l e a d o t h e r s.
b. a s u c c e s s f u l a t t e m p t t o m i s l e a d o t h e r s.
c. a failure to distinguish a fact from an opinion.
d. it changes depending on the situation.
Quiz Questions
Ve r s i o n C
1 . Wr i t e a n e x a m p l e o f a s c i e n t i f i c wo r k i n g d e f i n i t i o n o f a l i e .
2. Select three physical signs of increased mental effort that are
f r e q u e n t l y s i g n s o f l y i n g. I f y o u w e r e a j u d g e i n a c o u r t c a s e , i n a d d i t i o n
to these signs what else would you want to obser ve about the person in
order to deter mine whether she or he was telling the tr uth?
3. Select one of the following groups of people and explain how
something we discussed in class might help members of this group in
t h e i r d a i l y wo r k o r p e r s o n a l l i v e s.
Po l i c e o f f i c e r s
Criminals
Te a c h e r s
Pa rents
Children