European Journal of Public Health, Vol. 19, No. 1, 2–4
ß The Author 2009. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.
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Viewpoint
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Denialism: what is it and how should scientists respond?
Black is white and white is
black
HIV does not cause AIDS. The world
was created in 4004 BCE. Smoking does
not cause cancer. And if climate change
is happening, it is nothing to do with
man-made CO2 emissions. Few, if any,
of the readers of this journal will believe
any of these statements. Yet each can be
found easily in the mass media.
The consequences of policies based on
views such as these can be fatal. Thabo
Mbeki’s denial that that HIV caused
AIDS prevented thousands of HIV
positive mothers in South Africa
receiving anti-retrovirals so that they,
unnecessarily, transmitted the disease to
their children.1 His health minister,
Manto Tshabalala-Msimang, famously
rejected evidence of the efficacy of
these drugs, instead advocating treatment with garlic, beetroot and African
potato. It was ironic that their departure
from office coincided with the award
of the Nobel Prize to Luc Montagnier
and Françoise Barré-Sinoussi for their
discovery that HIV is indeed the case of
AIDS. The rejection of scientific evidence is also apparent in the popularity
of creationism, with an estimated 45%
of Americans in 2004 believing that God
created man in his present form within
the past 10 000 years.2 While successive
judgements of the US Supreme Court
have rejected the teaching of creationism
as science, many American schools are
cautious about discussing evolution.
In the United Kingdom, some faithbased schools teach evolution and creationism as equally valid ‘faith positions’.
It remains unclear how they explain
the emergence of antibiotic resistance.
Elsewhere, the hand of powerful
corporate interests can be seen. It took
many decades for the conclusions of
authoritative reports by the US Surgeon
General3 and the British Royal College
of Physicians4 on the harmful effects of
smoking to be accepted, while even now,
despite clear evidence of rapid reductions in myocardial infarctions where
bans have been implemented, there are
some who deny that second-hand smoke
is dangerous. In large part this was due
to the efforts of the tobacco industry to
deflect attention to other putative causes
of smoking-related diseases, from stress
to keeping pet birds. The reports of the
Intergovernmental Panel on Climate
Change have suffered similar attacks
from commentators with links to
major oil companies.
All of these examples have one feature
in common. There is an overwhelming
consensus on the evidence among
scientists yet there are also vocal commentators who reject this consensus,
convincing many of the public, and
often the media too, that the consensus
is not based on ‘sound science’ or
denying that there is a consensus by
exhibiting individual dissenting voices
as the ultimate authorities on the topic
in question. Their goal is to convince
that there are sufficient grounds to
reject the case for taking action to
tackle threats to health. This phenomenon has led some to draw a historical
parallel with the holocaust, another area
where the evidence is overwhelming
but where a few commentators have
continued to sow doubt. All are seen
as part of a larger phenomenon of
denialism.
Defining and recognizing
denialism
The Hoofnagle brothers, a lawyer and
a physiologist from the United States,
who have done much to develop the
concept of denialism, have defined it
as the employment of rhetorical arguments to give the appearance of legitimate debate where there is none,5 an
approach that has the ultimate goal
of rejecting a proposition on which a
scientific consensus exists.6 In this
viewpoint, we argue that public health
scientists should be aware of the features
of denialism and be able to recognize
and confront it.
Denialism is a process that employs
some or all of five characteristic
elements in a concerted way. The first
is the identification of conspiracies.
When the overwhelming body of scientific opinion believes that something is
true, it is argued that this is not because
those scientists have independently
studied the evidence and reached the
same conclusion. It is because they have
engaged in a complex and secretive
conspiracy. The peer review process is
seen as a tool by which the conspirators
suppress dissent, rather than as a means
of weeding out papers and grant
applications unsupported by evidence
or lacking logical thought. The view of
General Jack D Ripper that fluoridation
was a Soviet plot to poison American
drinking water in Dr Strangelove,
Kubrick’s black comedy about the Cold
War is no less bizarre than those
expressed in many of the websites that
oppose this measure.
In some cases, denialism exploits
genuine concerns, such as the rejection
of evidence on the nature of AIDS by
African-Americans who perceive them
as a manifestation of racist agendas.7
While conspiracy theories cannot
simply be dismissed because conspiracies do occur,8 it beggars belief
that they can encompass entire scientific
communities.
There is also a variant of conspiracy
theory, inversionism, in which some
of one’s own characteristics and motivations are attributed to others. For
example, tobacco companies describe
academic research into the health effects
of smoking as the product of an
‘anti-smoking industry’, described as
‘a vertically integrated, highly concentrated, oligopolistic cartel, combined
with some public monopolies’ whose
aim is to ‘manufacture alleged evidence,
suggestive inferences linking smoking to
various diseases and publicity and
dissemination and advertising of these
so-called findings to the widest possible
public’.9
The second is the use of fake experts.
These are individuals who purport to be
experts in a particular area but whose
views are entirely inconsistent with
established knowledge. They have been
used extensively by the tobacco industry
since 1974, when a senior executive with
R J Reynolds devised a system to score
scientists working on tobacco in relation
to the extent to which they were supportive of the industry’s position. The
industry embraced this concept enthusiastically in the 1980s when a senior
executive from Philip Morris developed
a strategy to recruit such scientists
(referring to them as ‘Whitecoats’) to
help counteract the growing evidence
on the harmful effects of second-hand
smoke. This activity was largely undertaken through front organizations
whose links with the tobacco industry
were concealed, but under the direction
of law firms acting on behalf of the
Viewpoint
tobacco industry.10 In some countries,
such as Germany, the industry created
complex and influential networks,
allowing it to delay the implementation of tobacco control policies for
many years.11 In 1998, the American
Petroleum Institute developed a Global
Climate Science Communications Plan,
involving the recruitment of ‘scientists
who share the industry’s views of
climate science [who can] help convince
journalists, politicians and the public
that the risk of global warming is too
uncertain to justify controls on greenhouse gases’.12 However, this is not
limited to the private sector; the administration of President George W Bush
was characterized by the promotion of
those whose views were based on their
religious beliefs or corporate affiliations,13 such as the advisor on reproductive health to the Food and Drug
Administration who saw prayer and
bible reading as the answer to premenstrual syndrome.14 A related
phenomenon is the marginalization of
real experts, in some cases through an
alliance between industry and government, as when ExxonMobil successfully
opposed the reappointment by the US
government of the chair of the
Intergovernmental Panel on Climate
Change.15,16 These events led a group
of prominent American scientists to
state that ‘stacking these public committees out of fear that they may offer
advice that conflicts with administration
policies devalues the entire federal
advisory committee structure’.17
The use of fake experts is often
complemented by denigration of established experts and researchers, with
accusations and innuendo that seek to
discredit their work and cast doubt
on their motivations. Stanton Glantz,
professor of medicine at the University
of California, San Francisco and who
has made a great contribution to
exposing tobacco industry tactics, is a
frequent target for tobacco denialists.
He is described on the Forces website as
‘infamous for being the boldest of liars
in ‘‘tobacco control’’ that most ethically
challenged gang of con artists’, adding
that ‘he cynically implies his research
into smoking is science, banking on the
sad fact that politicians, let alone the
media, have no idea that epidemiology
is not real science and that his studies
define the term junk science’.18
The third characteristic is selectivity,
drawing on isolated papers that challenge the dominant consensus or highlighting the flaws in the weakest papers
among those that support it as a means
of discrediting the entire field. An
example of the former is the muchcited
Lancet
paper
describing
intestinal abnormalities in 12 children
with autism, which merely suggested a
possible link with immunization against
measles, mumps and rubella.19 This has
been used extensively by campaigners
against immunization, even though 10
of the paper’s 13 authors subsequently
retracted the suggestion of an association.20 Fortunately, the work of the
Cochrane Collaboration in promoting
systematic reviews has made selective
citation easier to detect.
Another is a paper published by the
British Medical Journal in 2003,21 later
shown to suffer from major flaws,
including a failure to report competing
interests,22 that concluded that exposure
to tobacco smoke does not increase the
risk of lung cancer and heart disease.
This paper has been cited extensively by
those who deny that passive smoking
has any health effects, with the company
Japan Tobacco International still quoting it as justification for rejecting ‘the
claim that ETS is a cause of lung cancer,
heart disease and chronic pulmonary
diseases in non-smokers’ as late as the
end of 2008.23
Denialists are usually not deterred by
the extreme isolation of their theories,
but rather see it as the indication of their
intellectual courage against the dominant orthodoxy and the accompanying
political correctness, often comparing
themselves to Galileo.
The fourth is the creation of impossible expectations of what research can
deliver. For example, those denying
the reality of climate change point to
the absence of accurate temperature
records from before the invention of
the thermometer. Others use the intrinsic uncertainty of mathematical models
to reject them entirely as a means of
understanding a phenomenon. In the
early 1990s, Philip Morris tried to
promote a new standard, entitled Good
Epidemiological Practice (GEP) for the
conduct of epidemiological studies.
Under the GEP guidelines, odds ratios
of 2 or less would not be considered
strong enough evidence of causation,
invalidating in one sweep a large body of
research on the health effects of many
exposures.24 Although Philip Morris
eventually scaled back its GEP programme, as no epidemiological body
would agree to such a standard, British
American Tobacco still uses this criterion to refute the risk associated with
passive smoking.25
The fifth is the use of misrepresentation and logical fallacies. For example,
pro-smoking groups have often used
the fact that Hitler supported some antismoking campaigns to represent those
advocating tobacco control as Nazis
(even coining the term nico-nazis),26
3
even though other senior Nazis were
smokers, blocking attempts to disseminate anti-smoking propaganda and
ensuring that troops has sufficient
supplies of cigarettes.27 Logical fallacies
include the use of red herrings, or
deliberate attempts to change the argument and straw men, where the opposing argument is misrepresented to make
it easier to refute. For example, the US
Environmental
Protection
Agency
(EPA) determined in 1992 that environmental tobacco smoke (ETS) is carcinogenic, a finding confirmed by many
other authoritative national and international public health institutions.
The EPA assessment was described by
two commentators as an ‘attempt to
institutionalize a particular irrational
view of the world as the only legitimate
perspective, and to replace rationality
with dogma as the legitimate basis of
public policy’, which they labelled as
nothing less than a ‘threat to the very
core of democratic values and democratic public policy’.28 Other fallacies
used by denialists are false analogy,
exemplified by the argument against
evolution that, as the universe and
a watch are both extremely complex,
the universe must have been created by
the equivalent of a watchmaker and the
excluded middle fallacy (either passive
smoking causes a wide range of specified
diseases or causes none at all, so doubt
about an association with one disease,
such as breast cancer, is regarded as
sufficient to reject an association with
any disease).
Responding to denialism
Denialists are driven by a range of
motivations. For some it is greed, lured
by the corporate largesse of the oil
and tobacco industries. For others it is
ideology or faith, causing them to reject
anything incompatible with their fundamental beliefs. Finally there is eccentricity and idiosyncrasy, sometimes
encouraged by the celebrity status conferred on the maverick by the media.
Whatever the motivation, it is important to recognize denialism when confronted with it. The normal academic
response to an opposing argument is to
engage with it, testing the strengths and
weaknesses of the differing views, in
the expectations that the truth will
emerge through a process of debate.
However, this requires that both parties
obey certain ground rules, such as a
willingness to look at the evidence as
a whole, to reject deliberate distortions
and to accept principles of logic. A meaningful discourse is impossible when
one party rejects these rules. Yet it
would be wrong to prevent the denialists
4
European Journal of Public Health
having a voice. Instead, we argue, it is
necessary to shift the debate from the
subject under consideration, instead
exposing to public scrutiny the tactics
they employ and identifying them
publicly for what they are. An understanding of the five tactics listed
above provides a useful framework for
doing so.
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Apt CC. The anti-smoking industry, Philip
Morris internal report dated September 1983;
Pascal Diethelm1, Martin McKee2
OxyGenève, Geneva, Switzerland 2London
School of Hygiene and Tropical Medicine,
London, UK
1
Correspondence: Martin McKee,
e-mail:
[email protected]
doi:10.1093/eurpub/ckn139