michaelshermer.com
Michael Shermer
Michael Shermer
How our modular brains lead us to deny and distort
evidence
January 1, 2013
IF YOU HAVE PONDERED how intelligent and educated people can,
in the face of overwhelming contradictory evidence, believe that that evolution
is a myth, that global warming is a hoax, that vaccines cause autism and
asthma, that 9/11 was orchestrated by the Bush administration, conjecture no
more. The explanation is in what I call logic-tight compartments—modules
in the brain analogous to watertight compartments in a ship.
The concept of compartmentalized brain functions acting either
in concert or in conflict has been a core idea of evolutionary psychology since
the early 1990s. According to University of Pennsylvania evolutionary
psychologist Robert Kurzban in Why
Everyone (Else) Is a Hypocrite (Princeton University Press, 2010),
the brain evolved as a modular, multitasking problem-solving organ—a Swiss Army
knife of practical tools in the old metaphor or an app-loaded iPhone in
Kurzban’s upgrade. There is no unified “self” that generates internally
consistent and seamlessly coherent beliefs devoid of conflict. Instead we are a
collection of distinct but interacting modules often at odds with one another.
The module that leads us to crave sweet and fatty foods in the short term is in
conflict with the module that monitors our body image and health in the long
term. The module for cooperation is in conflict with the one for competition,
as are the modules for altruism and avarice or the modules for truth telling
and lying.
Compartmentalization is also at work when new scientific
theories conflict with older and more naive beliefs. In the 2012 paper “Scientific Knowledge
Suppresses but Does Not Supplant Earlier Intuitions” in the journal Cognition,
Occidental College psychologists Andrew Shtulman and Joshua Valcarcel found
that subjects more quickly verified the validity of scientific statements when
those statements agreed with their prior naive beliefs. Contradictory
scientific statements were processed more slowly and less accurately,
suggesting that “naive theories survive the acquisition of a mutually
incompatible scientific theory, coexisting with that theory for many years to
follow.”
Cognitive dissonance may also be at work in the
compartmentalization of beliefs. In the 2010 article “When in
Doubt, Shout!” in Psychological Science, Northwestern
University researchers David Gal and Derek Rucker found that when subjects’
closely held beliefs were shaken, they “engaged in more advocacy of their
beliefs … than did people whose confidence was not undermined.” Further, they
concluded that enthusiastic evangelists of a belief may in fact be “boiling
over with doubt,” and thus their persistent proselytizing may be a signal that
the belief warrants skepticism.
In addition, our logic-tight compartments are influenced by
our moral emotions, which lead us to bend and distort data and evidence through
a process called motivated reasoning. The module housing our
religious preferences, for example, motivates believers to seek and find facts
that support, say, a biblical model of a young earth in which the overwhelming
evidence of an old earth must be denied. The module containing our political
predilections, if they are, say, of a conservative bent, may motivate
procapitalists to believe that any attempt to curtail industrial pollution by
way of the threat of global warming must be a liberal hoax.
What can be done to break down the walls separating our
logic-tight compartments? In the 2012 paper “Misinformation and Its Correction:
Continued Influence and Successful Debiasing” in Psychological Science
in the Public Interest, University of Western Australia psychologist
Stephan Lewandowsky and his colleagues suggest these strategies: “Consider what
gaps in people’s mental event models are created by debunking and fill them using
an alternative explanation…. To avoid making people more familiar with
misinformation…, emphasize the facts you wish to communicate rather than the
myth. Provide an explicit warning before mentioning a myth, to ensure that
people are cognitively on guard and less likely to be influenced by the
misinformation…. Consider whether your content may be threatening to the
worldview and values of your audience. If so, you risk a worldview backfire
effect.”
Debunking by itself is not enough. We must replace bad bunk
with sound science.
