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 below.) The results suggest that individuals who are most adept at scientific reasoning
search out evidence to support their cultural dispositions.
Source: Dan Kahan, 'What is the science of science communication', Journal of Science Communication, 2015 |
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 colourings, 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.
That leaves those of us who accept the physics of the
greenhouse effect with great difficulty in assessing the urgency of the threat
to humanity that it may involve. It is
easy enough to find 22 ways to think about the climate debate, but it isn’t
easy to find a dispassionate expert overview of the relevant science. Nearly
all leading scientists seem to have become preachers.
When scientists seek to persuade people to adopt particular
positions on contentious policy issues it is inevitable that they will be seen
to be preaching rather than presenting information on the current state of
knowledge. If scientists want to be listened to by people other than their
political cheer squads of “true believers” they should distance themselves from
policy debate and display some modesty about the quality of their conjectures.