Hi, my name is Kyle MacDonald.
I’m a PhD student in developmental psychology
at Stanford.
And in this video I’m going to be talking
to you about a fundamental component of human
psychology called Theory of Mind.
But first, let’s start with an important
question: How do we know what other people
are thinking?
After all, we have no way of directly observing
what’s going on inside of their heads.
But what we can do is observe other people’s
actions and use that information to make guesses
about what they are thinking.
One intuitive example is when we see a stranger
waving at us, we might guess at things like
whether or not: He knows me?
He wants me to wave back?
Or maybe he’s not actually waving at me
at all, but waving at someone behind me?
And importantly, we will make all of these
inferences quite easily and quite rapidly.
Philosophers and researchers have called the
general process of theorizing about other
people’s mental states: theory of mind.
Broadly defining it as the ability to attribute
beliefs, desires, and knowledge to oneself
and to others.
With the understanding that others can have
mental states that are different from your
own.
But what does it mean to have a “theory”
of mind?
And how does it work in the real world?
Well, just like theories in science, theory
of mind allows you to explain other people’s
behavior and to make predictions about what
they will do in new situations.
So for example, if you see someone choose
to eat chocolate ice cream, you will explain
their behavior as an internal preference for
chocolate.
And you can now use this part of theory of
mind to predict that they might be likely
to select chocolate ice cream over mint chip
in the future.
It is easy to think about how explaining and
predicting behavior would be a useful skill
in many situations.
But what does theory of mind look like in
kids?
Well, similar to most skills, children need
time and experience with the world to develop
their theory of mind abilities.
One good example of children’s immature
theory of mind comes from games of hide and
go seek, where children will often hide in
plain sight but cover their eyes.
In this scenario, the child has failed to
consider that just because he can’t see,
doesn’t mean that other people around him
can’t see.
Which makes for a short game.
So from these kinds of behaviors, it is clear
that children’s theory of mind abilities
are still developing, and researchers have
come up with clever methods to measure these
changes
One classic test is the False Belief task.
In this game, children meet two characters:
Bobby and Susie, and Bobby has a green box
and Susie has a blue box.
Bobby takes one of his toys and puts it inside
the green box before leaving the room to go
for a walk.
Susie then takes the toy and moves it from
the green box to the blue box.
After the change of location, Bobby comes
back and wants to play with his toy.
And the child is asked: Where will Bobby look
for his toy?
The prediction is that children who understand
that Bobby could hold a “False Belief”
will say that he will look in the Green box
where he last saw his toy.
Whereas, children who do not have this understanding
say he will look in the Blue box, “failing”
to appreciate Bobby’s false belief.
Using this method, researchers have found
a robust developmental pattern, where 3 year
olds tend to fail this task, but 4 year olds
reliably pass it.
And this finding has led to theoretical accounts
that emphasize a conceptual shift in children’s
theory of mind abilities around this age.
But is there evidence of earlier false belief
understanding in infancy?
And how do we measure it?
In a recent experiment, Kristine Onishi and
Renee Baillargeon created a false belief task
more appropriate for infants, by using a violation
of expectation paradigm that uses infants’
looking times as a measure of surprise.
In their task, the first familiarized infants
to one adult hiding and retrieving a toy from
two boxes.
Then, in phase 2, the toy was moved from one
box to the other.
The critical manipulation was that in the
True-Belief condition, the adult could see
the toy change location.
But in the False-Belief condition, she could
not.
Finally, in the test phase, infants either
saw the adult reach into the box where the
toy was located or was not located.
The key prediction is that infants should
look longer when the adult performed a “surprising”
action, either by reaching to the incorrect
location in the True Belief condition, even
though she knew where the toy was.
Or by reaching to the correct location in
the False Belief condition, even though she
had not seen the toy being moved there.
These results suggest that toddlers may already
have some understanding that others act on
the basis of their beliefs and that these
beliefs may or may not accurately reflect
the true state of the world.[d]
So how do we explain preschoolers’ lack
of success on classic False Belief tasks when
infants seem to show basic understanding of
others’ beliefs?
One possibility is that there are two systems
-- an implicit and explicit theory of mind.
With the implicit system being early learned
or innate, and the explicit system learned
more slowly.
Another possibility is complete continuity
in children’s theory of mind abilities.
In this explanation, preschoolers’ failures
are seen as artifacts of experimental tasks
that are too difficult for the child to understand.
The current evidence suggests complete continuity.
But no one study has provided conclusive evidence
and the research is ongoing.
So to wrap up, we started with a big question:
How do humans take observable behavior and
turn them into rich inferences about what
other people are thinking?
And we learned that people have a set of tools
called Theory of Mind that allows them to
reason about others’ goals, beliefs and
desires.
Which in turn allow them to explain behavior
and to make predictions about what people
will do in the future.
Finally, we saw that children’s Theory of
Mind skills are developing in the first years
of life, but there is some evidence of early
False Belief understanding if the task is
simple and slow enough for toddlers to understand.
It’s important to point out that there are
active debates about the best way to characterize
our Theory of Mind capabilities, and not all
researchers think that we use actual theories
to interpret others’ behavior.
However, we can conclude that often we are
able to rapidly figure out what people have
in their heads that cause them to do the things
they do, which is pretty cool!
That’s all!
Thanks for watching!
