September 2019, ScientificAmerican.com 61the growing consensus that smoking kills. During the
1950s and 1960s the Tobacco In stitute published a bi-
monthly newsletter called “To bacco and Health” that
re ported only scientific research suggesting tobacco
was not harmful or research that emphasized uncer-
tainty regarding the health eff ects of tobacco.
The pamphlets employ what we have called selective
sharing. This approach involves taking real, indepen-
dent scientific research and curating it, by presenting
only the evidence that favors a preferred position. Using
variants on the models described earlier, we have argued
that selective sharing can be shockingly effective at shap-
ing what an audience of nonscientists comes to believe
about scientific matters of fact. In other words, motivat-
ed actors can use seeds of truth to create an impression
of uncertainty or even convince people of false claims.
Selective sharing has been a key part of the anti-
vaxxer playbook. Before the recent measles outbreak in
New York, an organization calling itself Parents Edu-
cating and Advocating for Children’s Health (PEACH)
produced and distributed a 40-page pamphlet entitled
“The Vaccine Safety Handbook.” The information
shared—when accurate—was highly selective, focus-
ing on a handful of scientific studies suggesting risks
as sociated with vaccines, with minimal consideration
of the many studies that find vaccines to be safe.
The PEACH handbook was especially effective be-
cause it combined selective sharing with rhetorical
strategies. It built trust with Orthodox Jews by project-
ing membership in their community (though published
pseudonymously, at least some authors were members)
and emphasizing concerns likely to resonate with them.
It cherry-picked facts about vaccines in tended to re-
pulse its particular audience; for instance, it noted that
some vaccines contain gelatin derived from pigs. Wit-
tingly or not, the pamphlet was designed in a way that
exploited social trust and conformism—the very mech-
anisms crucial to the creation of human knowledge.
Worse, propagandists are constantly developing
ever more sophisticated methods for manipulating
public belief. Over the past several years we have seen
purveyors of disinformation roll out new ways of cre-
ating the impression—especially through social media
conduits such as Twitter bots and paid trolls and, most
recently, by hacking or copying your friends’ accounts
that certain false beliefs are widely held, including by
your friends and others with whom you identify. Even
the PEACH creators may have encountered this kind of
synthetic discourse about vaccines. According to a 2018
article in the American Journal of Public Health, such
disinformation was distributed by accounts linked to
Russian influence operations seeking to amplify Amer-
ican discord and weaponize a public health issue. This
strategy works to change minds not through rational
arguments or evidence but simply by manipulating the
social spread of knowledge and belief.
The sophistication of misinformation efforts (and
the highly targeted disinformation campaigns that
amplify them) raises a troubling problem for democ-
racy. Returning to the measles example, children in
many states can be exempted from mandatory vacci-
nations on the grounds of “personal belief.” This be-
came a flash point in California in 2015 following a
measles outbreak traced to unvaccinated children vis-
iting Disneyland. Then governor Jerry Brown signed a
new law, SB277, removing the exemption.
Immediately vaccine skeptics filed paperwork to
put a referendum on the next state ballot to overturn
the law. Had they succeeded in getting 365,880 signa-
tures (they made it to only 233,758), the question of
whether parents should be able to opt out of man-
datory vaccination on the grounds of personal belief
would have gone to a direct vote—the results of which
would have been susceptible to precisely the kinds of
disinformation campaigns that have caused vacci-
nation rates in many communities to plummet.
Luckily, the effort failed. But the fact that hundreds
of thousands of Californians supported a direct vote
about a question with serious bearing on public health,
where the facts are clear but widely misconstrued by
certain activist groups, should give serious pause.
There is a reason that we care about having policies
that best reflect available evidence and are responsive
to reliable new information. How do we protect public
well-being when so many citizens are misled about
matters of fact? Just as individuals acting on misinfor-
mation are un likely to bring about the outcomes they
desire, societies that adopt policies based on false belief
are unlikely to get the results they want and expect.
The way to decide a question of scientific fact—are
vaccines safe and effective?—is not to ask a communi-
ty of nonexperts to vote on it, especially when they are
subject to misinformation campaigns. What we need
is a system that not only respects the processes and in-
stitutions of sound science as the best way we have of
learning the truth about the world but also respects
core democratic values that would preclude a single
group, such as scientists, dictating policy.
We do not have a proposal for a system of govern-
ment that can perfectly balance these competing con-
cerns. But we think the key is to better separate two
essentially different issues: What are the facts, and
what should we do in light of them? Democratic ideals
dic tate that both require public oversight, trans-
parency and account ability. But it is only the second—
how we should make decisions given the facts—that
should be up for a vote.MORE TO EXPLORE
The Wisdom and/or Madness of Crowds. Nicky Case. Interactive game for
network contagion: https://ncase.me/crowds
Weaponized Health Communication: Twitter Bots and Russian Trolls
Amplify the Vaccine Debate. David A. Broniatowski et al. in American
Journal of Public Health, Vol. 108, No. 10, pages 1378–1384; October 2018.
FROM OUR ARCHIVES
The Power of Memes. Susan Blackmore; October 2000.
ä`x³î
`Dxß`D³Í` ̧êDDą³xêäDköć¿ ́3`x³î
` xß`D³