Is Your Face a Window to Your Soul?
So physiognomy or the so-called pseudoscience
to feed in character from faces has a very very long history.
The first historical document date all the way
back to the time of Aristotle.
But it really got extremely extremely popular in the 18th and 19th century.
And for a while,
so there were quite a few studies
in the beginning of the 20th century,
we are talking about twenties and the thirties,
by psychologist finding very very little
evidence for the accuracy of physiognomic inferences.
And recently there was for example,
a computer science paper claiming that presumably
you can guess whether a person is a criminal or not
based on their facial image.
And actually the history of identifying the criminal
has a very very long history in physiognomy.
There’s lots of lots of studies
showing effects of appearance across different domains.
In my own lab, more than 10 years ago,
we showed that you can predict electoral success
based on judgement from the appearance of politicians.
Then there have been many other studies in the legal domain.
So for example, a recent study show that
prisoners who were sentenced to death
for the same crime as those who were sentenced to a
a life sentence without parole,
the main difference was the prisoners
who were sentenced to death look less trustworthy.
There’s been a lot of evidence in economic game.
So for example,
economists love this sort of economic games
where we have any interactions.
And if I don’t know anything about you,
I have a risky choice whether to invest in you or not.
If I invest, and you are trustworthy,
then we are both better off.
But if you are untrustworthy,
you can take away my money and run away.
So it’s… it creates this risk situation.
And many studies suggest that in fact,
if…we think if the appearance of the other person is untrustworthy,
we tend not to invest in these people.
Interestingly, there was a study
that was done in Germany in Switzerland
when in fact people played anonymously.
And they also did different measurements of the faces.
Turns out that these measurements that are supposed
to predict untrustworthiness or aggressiveness
didn’t predict at all how people will behave
in this kind of anonymous economic game.
The interesting part is that these participants,
they were incentivized for accurate responses.
And, so for every accurate response,
they were essentially trying to predict
what the person did in the situation.
They ended up losing money
because they were relying on these kinds of appearence.
But you can see how in the real life situation,
you can have all kinds of self-fulfilling prophecies.
So we come and play with you in a game.
I decided for some reason that you are untrustworthy.
So my first move is not cooperative move.
Well, you reciprocate in a similar way.
“I don’t trust you, so why would you trust me?”
And that kinds of leads to a self-fulfilling prophecy.
So you can create this kind of dynamic
dynamic inconsistency in the situation
where in fact the people could be perfectly trustworthy and might cooperate,
but the appearance cues can get into the way.
Now, to the extent that you agree in these impressions,
an important empirical question is well
what is the, where is this agreement coming from?
And so in the past decades we have built mathematical models,
and other groups have built their own models that
essentially are trying to discover
the cues that people are using
when they form these impressions.
So what kinds of cues you can observe?
Well, when you are deciding whether somebody is trustworthy or not,
one of the most important input is emotional expressions.
So often in psychology we talk about
that there’s emotional neutral faces and
there’s faces expressing different emotions.
But the fact of the matter is that
an emotional neutral face is a fiction,
is a psychological fiction.
You could be emotionally neutral,
but if you haven’t been sleep deprived,
you will look better.
If you have a nice day, you will look better,
even if you are not smiling.
So although the expressions might
not be explicit or exaggerated,
the way they’re typically studied,
in studies in emotional expressions,
there are subtle expressions on our faces.
So these expressions are very important input to impressions.
Notice they might be accurate,
these impressions at the particular moment here now.
But they would be very lousy,
as a guide to what the person is
in general across timing situations.
To get back to trustworthiness,
faces that look like they’re smiling,
they have a positive expressions,
they’re perceived more positively.
Faces that look disgruntle,
they’re perceived more negatively.
What are the other inputs?
Many of the other inputs come from stereotypes.
For example, feminine faces are perceived as
more trustworthy than masculine faces.
On the other hand,
masculine faces are perceived as more dominant.
So there are lots of and lots of cues
and there are cues that actually completely
you think corrective to others.
faces that resemble people that you already like，
you will tend to like,
not knowing anything about this people.
And the other way around,
faces that resemble people that you dislike,
you will tend not to like,
bearing no other information about this people.