Even when we're wrong
ETH
Zurich
Buying a second-hand car at a good price feels good. But choosing a delicious-looking doughnut in the supermarket leaves us riddled with doubt.
After all, we resolved to eat a healthier diet this year -- so wouldn't it be
better to buy an apple? We've all experienced this feeling at one time or
another: some decisions intuitively feel right, while others leave us feeling
doubtful and may even cause us to revise our initial choice. But where does
this feeling come from?
For
the first time, a team of researchers at ETH Zurich and the University of
Zurich led by ETH Professor Rafael Polanía has investigated this question
systematically. The authors used experimental data to develop a computer model
that can predict how an individual will choose between different options and
why they might subsequently feel confident or doubtful about the decision they
made.
"Using our model, we've successfully shown that decisions are most likely to feel right if we have invested significant attentional effort in weighing up the different options and, what's more, are conscious of having done so," says Polanía, who heads up the Decision Neuroscience Lab at ETH Zurich.
Consequently,
the ability to question and revise poor decisions depends on how well we are
able to judge for ourselves whether we thoroughly weighed up the options or allowed
ourselves to be distracted during the decision-making process. This
self-awareness, which experts typically refer to as introspection, is an
essential prerequisite for self-control.
Examining
subjective evaluations of choice in the lab
The
confidence we have in our own decisions is based on subjective value
estimations that we typically make automatically and unquestioningly as part of
our day-to-day lives. To enable a systematic analysis of how this process
works, Polanía and his team studied how test subjects evaluate and select
everyday foods.
The
35 study participants were initially asked to evaluate 64 products from two
Swiss supermarket chains. They were presented with a picture of each product on
screen and asked how much they would like to eat it at the end of the
experiment. In the second part of the experiment, the test subjects were shown
a series of pictures that showed two products at the same time. In each case,
they were asked to choose one of the two options -- doughnut or apple, pizza or
pear -- and then rate how much confidence they had in their decision.
To
make the experiment as realistic as possible, the participants had to eat the
products after the experiment. The researchers used an eye scanner during both
the evaluation and decision-making phases to determine whether the
participants spent longer looking at one of the two products, how often their
gaze shifted from left to right, and how quickly they made their decision.
Higher
attentional effort leads to greater confidence
Using
this data and a similar dataset from a different research group, Polanía
together with his PhD student Jeroen Brus developed a computer model that can
predict under which conditions people will have confidence -- or a lack thereof
-- in their decisions. "We discovered that people are particularly likely
to have a bad feeling about a decision if they introspect that they didn't pay
enough attention to comparing the different options," Polanía says.
The
model uses the patterns of participants' eye movements to determine how much
effort they actually put into evaluating and comparing the different products.
Someone who takes their time and always keeps both options in their sights is
considered to have invested high attentional effort, while those who tend to
fixate on just one option and neglect the other are regarded as having been
less attentive.
The
best way to illustrate these findings is by considering an example from
everyday life: if we unthinkingly add a doughnut to our shopping basket, even
after expressing an intention to eat more healthily, and subsequently realise
that we didn't even think about healthier alternatives, we ought to have low
confidence in our decision and revise it. If, on the other hand, we are
conscious of having carefully considered a series of healthier products but
then decided against them because we simply wanted the doughnut more than an
apple or pear, we should have confidence in our decision.
Using
introspection to revise poor decisions
According
to the study's authors, the ability to question poor decisions and have
confidence in good ones depends to a large extent on how conscious an
individual is of their subjective value judgements and comparisons after making
a decision. This is something neuroscientists refer to as introspection.
"Once
we've made a decision, we can feel doubtful as to its value and revise it only
if we're actually conscious of the fact that we failed to pay enough attention
to comparing the options," Polanía says. This capacity for introspection
is also a crucial part of our ability to exercise self-control. Without it,
Polanía says, we would be far more likely to act on our preferences for, say,
unhealthy foods without questioning them. The good news is that we can train
this ability through mindfulness exercises and meditation.
Applications
in smart glasses and self-driving vehicles
Polanía
says this model could eventually be incorporated into smart glasses that track
eye movements. "The glasses could use the model to determine how attentive
we're being and let us know when we should question a decision," he says.
Polanía
also believes the model could be useful for self-driving cars. The algorithms
used in autonomous vehicles are constantly making decisions based on a
continuous stream of data from the vehicle's sensors. "Our model could
help the vehicle evaluate its decisions and revise them where necessary,"
Polanía says.
