By Philip Fernbach and Steven Sloman
March 3, 2017
How can so many people believe things that
are demonstrably false? The question has taken on new urgency as the Trump
administration propagates falsehoods about voter fraud, climate change and
crime statistics that large swaths of the population have bought into. But
collective delusion is not new, nor is it the sole province of the political
right. Plenty of liberals believe, counter to scientific consensus, that
G.M.O.s are poisonous, and that vaccines cause autism.
The situation is vexing because it seems so
easy to solve. The truth is obvious if you bother to look for it, right? This
line of thinking leads to explanations of the hoodwinked masses that amount to
little more than name calling: “Those people are foolish” or “Those people are
Such accounts may make us feel good about
ourselves, but they are misguided and simplistic: They reflect a
misunderstanding of knowledge that focuses too narrowly on what goes on between
our ears. Here is the humbler truth: On their own, individuals are not well
equipped to separate fact from fiction, and they never will be. Ignorance is
our natural state; it is a product of the way the mind works.
What really sets human beings apart is not
our individual mental capacity. The secret to our success is our ability to
jointly pursue complex goals by dividing cognitive labor. Hunting, trade,
agriculture, manufacturing — all of our world-altering innovations — were made
possible by this ability. Chimpanzees can surpass young children on numerical
and spatial reasoning tasks, but they cannot come close on tasks that require
collaborating with another individual to achieve a goal. Each of us knows only a
little bit, but together we can achieve remarkable feats.
Knowledge Isn’t In My Head Or In Your
Head. It’s shared.
Consider some simple examples. You know
that the earth revolves around the sun. But can you rehearse the astronomical
observations and calculations that led to that conclusion? You know that
smoking causes cancer. But can you articulate what smoke does to our cells, how
cancers form and why some kinds of smoke are more dangerous than others? We’re
guessing no. Most of what you “know” — most of what anyone knows — about any
topic is a placeholder for information stored elsewhere, in a long-forgotten
textbook or in some expert’s head.
One consequence of the fact that knowledge
is distributed this way is that being part of a community of knowledge can make
people feel as if they understand things they don’t. Recently, one of us ran a
series of studies in which we told people about some new scientific discoveries
that we fabricated, like rocks that glow. When we said that scientists had not
yet explained the glowing rocks and then asked our respondents how well they
understood how such rocks glow, they reported not understanding at all — a very
natural response given that they knew nothing about the rocks. But when we told
another group about the same discovery, only this time claiming that scientists
had explained how the rocks glowed, our respondents reported a little bit more
understanding. It was as if the scientists’ knowledge (which we never
described) had been directly transmitted to them.
The sense of understanding is contagious.
The understanding that others have, or claim to have, makes us feel smarter.
This happens only when people believe they have access to the relevant
information: When our experimental story indicated that the scientists worked
for the Army and were keeping the explanation secret, people no longer felt
that they had any understanding of why the rocks glowed.
The key point here is not that people are
irrational; it’s that this irrationality comes from a very rational place.
People fail to distinguish what they know from what others know because it is
often impossible to draw sharp boundaries between what knowledge resides in our
heads and what resides elsewhere.
This is especially true of divisive
political issues. Your mind cannot master and retain sufficiently detailed
knowledge about many of them. You must rely on your community. But if you are
not aware that you are piggybacking on the knowledge of others, it can lead to
Recently, for example, there was a vociferous
outcry when President Trump and Congress rolled back regulations on the dumping
of mining waste in waterways. This may be bad policy, but most people don’t
have sufficient expertise to draw that conclusion because evaluating the policy
is complicated. Environmental policy is about balancing costs and benefits. In
this case, you need to know something about what mining waste does to waterways
and in what quantities these effects occur, how much economic activity depends
on being able to dump freely, how a decrease in mining activity would be made
up for from other energy sources and how environmentally damaging those are,
and on and on.
We suspect that most of those people
expressing outrage lacked the detailed knowledge necessary to assess the
policy. We also suspect that many in Congress who voted for the rollback were
equally in the dark. But people seemed pretty confident.
Such collective delusions illustrate both
the power and the deep flaw of human thinking. It is remarkable that large
groups of people can coalesce around a common belief when few of them
individually possess the requisite knowledge to support it. This is how we
discovered the Higgs boson and increased the human life span by 30 years in the
last century. But the same underlying forces explain why we can come to believe
outrageous things, which can lead to equally consequential but disastrous
That individual ignorance is our natural
state is a bitter pill to swallow. But if we take this medicine, it can be
empowering. It can help us differentiate the questions that merit real
investigation from those that invite a reactive and superficial analysis. It
also can prompt us to demand expertise and nuanced analysis from our leaders,
which is the only tried and true way to make effective policy. A better
understanding of how little is actually inside our own heads would serve us
Philip Fernbach is a cognitive scientist and professor of marketing at
the University of Colorado’s Leeds School of Business. Steven Sloman is a
professor of cognitive, linguistic and psychological sciences at Brown
University. They are the authors of the forthcoming “The Knowledge Illusion:
Why We Never Think Alone.”