60 Scientific American, September 2019
and those with poor beliefs fail to learn better ones.
Conformism, meanwhile, is a preference to act in
the same way as others in one’s community. The urge to
conform is a profound part of the human psyche and
one that can lead us to take actions we know to be
harmful. When we add conformism to the model, what
we see is the emergence of cliques of agents who hold
false beliefs. The reason is that agents connected to the
outside world do not pass along information that con-
flicts with their group’s beliefs, meaning that many
members of the group never learn the truth.
Conformity can help explain why vaccine skeptics
tend to cluster in certain communities. Some private
and charter schools in southern California have vacci-
nation rates in the low double digits. And rates are
startlingly low among Somali immigrants in Minneap-
olis and Orthodox Jews in Brooklyn—two communities
that have recently suffered from measles outbreaks.
Interventions into vaccine skepticism need to be
sensitive to both social trust and conformity. Simply
sharing new evidence with skeptics will likely not
help, because of trust issues. And convincing trusted
community members to speak out for vaccination
might be difficult because of conformism. The best ap-
proach is to find individuals who share enough in
common with members of the relevant communities
to establish trust. A rabbi, for instance, might be an ef-fective vaccine ambassador in Brooklyn, whereas in
southern California, you might need to get Gwyneth
Paltrow involved.
Social trust and conformity can help explain why
polarized beliefs can emerge in social networks. But at
least in some cases, including the Somali community
in Minnesota and Orthodox Jewish communities in
New York, they are only part of the story. Both groups
were the targets of sophisticated misinformation cam-
paigns designed by anti-vaxxers.%"7% '02 5'%3
HOW WE VOTE, what we buy and who we acclaim all de-
pend on what we believe about the world. As a result,
there are many wealthy, powerful groups and indivi-
duals who are interested in shaping public beliefs—
including those about scientific matters of fact. There is
a naive idea that when industry attempts to influence
scientific belief, they do it by buying off corrupt sci-
entists. Perhaps this happens sometimes. But a careful
study of historical cases shows there are much more
subtle—and arguably more effective—strategies that in-
dustry, nation states and other groups utilize. The first
step in protecting ourselves from this kind of mani-
pulation is to understand how these campaigns work.
A classic example comes from the tobacco industry,
which developed new techniques in the 1950s to fightIllustration by Bud CookIn statistics, we aren’t generally seeing
the whole universe but only a slice of it.
äD§§ä§`xøäøD§§ājÿ`` ̧ø§lîx§§D` ̧ǧxîx§ālxßx³îäî ̧ßāîD³
another small slice. We are trying to make a leap from these small slices to
a bigger truth. A lot of people take that basic unit of truth to be the p-value,
a statis tical measure of how surprising what we see in our small slice is, if our
as sumptions about the larger universe hold. But I don’t think that’s correct.
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threshold applied to the p-value, and it may have ver y little to do with sub-
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that provides that arbitrary threshold with meaning—it gives us a false
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behind that p-value.
One way to strengthen the p-value would be to shift the culture toward
transparency. If we not only report the p-value but also show the work on how
we got there—the standard error, the standard deviation or other measures
of uncertainty, for example—we can give a better sense of what that number
means. The more information we publish, the harder it is to hide behind that
p-value. Whether we can get there, I don’t know. But I think we should try.Nicole Lazar, a professor of statistics at the University of Georgia,
as told to Brooke BorelHOW A STATISTICIAN SEARCHES FOR ANSWERS