Source for graphic: Dan Kahan, 'What is the science of science communication', Journal of Science Communication, 2015
This is a slightly edited version of an essay I published
here about 10 years ago. It raises issues that are worth thinking about further
at this time.
When I hear scientists engaged in policy advocacy I often
cheer them on. At other times I make cynical comments questioning whether their
conjectures have any substance. I notice that other people seem to have similar
reactions, but some jeer when I cheer and vice versa.
In thinking about my own reactions I am able to rule out
some possible reasons for negativity without much difficulty.
Expertise: My reactions are not always closely
related to my own expertise. I can react positively or negatively to scientific
advocacy in relation to areas of public policy in which I have no expertise as
well as in aspects of economic policy where I can claim some expertise.
Conservatism: My reactions do not seem to be
consistently conservative in the sense of being cautious about change.
Sometimes I feel that scientists are setting out to make me worry unduly about
the implications of our current lifestyles, but I am less inclined to feel that
they are trying to make me feel more complacent than I should be about
potential adverse effects of various innovations e.g. GM food or health effects
of living close to power lines or wind farms.
Research funding: My reactions are not necessarily
related to the question of how the scientists fund their research. In some
instances I might suspect that they are advocating in the interests of the
people who have provided funding, or slanting their presentations to further
their interests in obtaining more funding, but such factors are not always
relevant.
Indoctrination: My reactions are unlikely to be
the result of indoctrination by particular branches of the news media. I am
exposed to a range of media organisations with a range of different biases.
I had to think more carefully about whether my reactions
could be related to the presentation skills of the scientists. I know I have a
strong allergic reaction to being preached at or manipulated. So, I took a look
at Jason
Nazar’s 21 principles of persuasion and some other web sites
discussing the art of persuasion. In the end I realized that I don’t have too
much difficulty these days in being able to appreciate the persuasive skills of
speakers while disagreeing with the messages they are presenting. I can also
support the message being presented by speakers while thinking they could do
with some help to improve their presentation skills. Membership of
Toastmasters encourages people to think about such matters.
It was not until I stumbled on an article by Dan Kahan
on the
science of science communication that I realized that the reactions
that people have to advocacy by scientists might be related to Bryan Caplan’s
concept of rational irrationality and Jonathan Haidt’s moral foundations theory
(which have previously been discussed on
this blog). Caplan suggests that people can have an almost religious
attachment to irrational beliefs about economics, while Haidt suggests that
identification with groups tends to blind people to the wisdom of people
outside those groups.
Cutting to the chase, Kahan tests the performance of two
hypotheses to explain why there is so much public dispute over science-based
conjectures about the risks that humans are facing. The first thesis, the
public irrationality thesis (PIT), predicts that the gap between public and
expert assessments of risk narrows as members of the public become more
literate about science. On that basis, people who scored highest on science
comprehension could be expected to be more concerned about climate change than
those with lower scores. However, this doesn’t happen - at least it doesn’t
happen in studies cited by the author.
The second thesis, the cultural cognition thesis (CCT)
posits that certain types of group affinities are integral to the mental
processes ordinary members of the public use to assess risk. Kahan cites
various studies that have tested CCT, but the results of one which tests CCT
head-to-head against PIT are particularly interesting. The results show that on
issues that have become politicized – such as global warming and fracking – the
average divergence between risk assessments of people who identify as liberal
democrats and conservative republicans is greater among those who have high
levels science comprehension than among those who have low levels of science
comprehension. (See chart at the top of this essay.)
The results suggest that individuals who are most adept at scientific reasoning
search out evidence to support their political dispositions.
The study suggests that there is little difference between
risk assessment of liberals and conservatives on issues that have not become
politicized e.g. artificial food colorings, exposure to radio waves from cell
phones, GM food, exposure to magnetic field of high voltage power lines, use of
artificial sweeteners and nanotechnology. The PIT thesis does apply to such
issues. I guess the results might differ in countries where some of these
issues, e.g. the risks associated with GM food, have become politicized.
So, in the light of the above, how should I react to
the Earth Statement recently
published by a group of eminent scientists which suggests that “2015 is a
critical year for humanity” and predicts dire consequences if international
forums to be held this year decide to postpone substantial reductions in
greenhouse gas emissions? Let me quote a paragraph:
“We can still avert dangerous climate change. However, we are currently on a warming trajectory that will leave our world irrevocably changed, far exceeding the 2°C mark. This gamble could propel us into completely uncharted waters, with unmanageable sea-level rise and a vastly different climate, including devastating heat waves, persistent droughts and unprecedented floods. The foundations of our societies, including food security, infrastructure, ecosystem integrity and human health, would be in jeopardy, impacting most immediately the poor and vulnerable.”
My immediate reaction was along the lines that they would
say that wouldn’t they. Those who preach about the end of the world can always
be expected to tell us to repent now for the end of the world is nigh. Would
you expect them to say that it is now too late to do avoid catastrophe, or that
there is no need to worry much for the next 20 years or so?
I claim no expertise in climate modelling, but the little I
know suggests to me that current models are not reliable enough to tell us that
it is critical that further action be initiated in 2015. Such claims seem to me
to be more like hysteria than science.
So, why don’t scientists take more care to avoid politicizing
science?
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