There is perhaps no greater source of authority in modern society than science. As a result, scientific claims are nearly ubiquitous, and often controversial. How do we decide when to trust and when to doubt ostensibly authoritative science?
This question was brought home to me in a couple of exchanges I’ve been part of this year concerning climate change and Alzheimer’s disease. When Peter Whitehouse recently wrote a post on the Myth of Alzheimer’s blog asserting that extreme weather events associated with climate change pose a significant threat to elders, particularly those with cognitive impairment, a climate change denier thanked him for exposing the myth of Alzheimer’s but took him to task for falling for the myth of global warming.
Going in the opposite direction, back in March someone took great offense at a talk I gave questioning the ostensibly authoritative claims of Alzheimer’s researchers and accused me of engaging in the equivalent of climate denial: making specious arguments that are dismissive of the very real problem Alzheimer’s disease presents to individuals and society, and thus reducing the global commitment needed to recognize and respond to it. (This exchange happened to take place as I was preparing for a four day bicycle trip with my 12-year-old daughter from central PA to Washington DC to raise awareness about the need for climate action, so it did get under my skin.)
It’s tempting to dismiss these criticisms as simple ignorance. After all, as I pointed out in reply to the same climate denier’s 30-link torrent in response to a subsequent post by Whitehouse on climate change, a very strong scientific consensus on anthropogenic climate change is in the realm of objective fact: A survey of nearly 12,000 relevant peer-reviewed scientific articles published from 1991-2011 show that 97% of them support the basic consensus on climate change, and virtually every prestigious scientific society in the United States and around the world has issued or signed on to statements supporting the consensus that climate change is being driven by emissions from the burning of fossil fuels and poses a serious threat to human society. And my criticism of the emphasis over the past thirty years in the Alzheimer’s field on cure and prevention rather than support for creative, stable caregiving hardly amounts to a denial that dementia is real, and causes real suffering and loss to society.
But a legitimate question remains. It seems that on the one hand, I am pleased to accept the claims of a majority of climate scientists as authoritative. On the other, I seem equally pleased to criticize the claims of a majority of scientists and practitioners in the Alzheimer’s field. How can I justify this apparent inconsistency? Perhaps I have enough direct familiarity with the content of the relevant branches of science in both of these broad fields to make an informed judgment? Absurd. I’m very knowledgeable about Alzheimer’s for a non-scientist, and probably better read than the average person on climate science. But the volume and degree of specialization in modern scientific research makes it a challenge for scientists to keep up with research even in their own narrow fields. Directly assessing the volume of work in broad fields like dementia or climate research is simple impossible. At some point, no matter how broad or thorough your scientific education and competency may be, you will need to trust (or not) the claims of others about science. But how to decide who and what to trust?
Here I think the academic fields that have formed me as a scholar – the history of medicine and STS (Science, Technology and Society) – have much to offer. The implicit idea of these fields is that understanding some of the science itself is necessary but far from sufficient. To understand science deeply enough to reach sound judgments about when to trust and when to question scientific claims, one must learn and think more about science and the way it is actually practiced in the world. One must understand the social and cultural contexts that shape scientific interest and help determine what kind of scientific questions are pursued. One must consider the social, economic and political factors that inevitably influence scientists. One must be able to recognize the way that social and cultural values are embedded in seemingly mundane questions of scientific method and analysis. The point of these sorts of questions is not to dismiss or diminish science, but to understand its real power, and in so doing reach better judgments about how it should be used to better serve human flourishing.
It’s the consideration of these sorts of questions that lead to my different stances toward climate science and Alzheimer’s research. As I mentioned above, in simple numerical terms the consensus on climate change is very strong. But in socio-historical terms, the breadth and resilience of the consensus is even more impressive. As shown by physicist and historian of science Spencer Weart’s comprehensive research, the consensus around the theory of anthropogenic climate change is not supported by evidence generated from the work of a single scientific field, but emerged with the convergence of many lines of research from a broad range of scientific fields ranging from geology, chemistry, atmospheric physics, meteorology, oceanography, computer modeling and many more. Practitioners in these fields use different methods and approaches to what counts as evidence, so that the theory has been challenged and tested from multiple directions. Scientists in different fields also get research funding from different sources within the federal government and the private sector, so the potential funding bias is less than when funding comes from a more narrow range of sources. Moreover, since the theory of anthropogenic climate change implicates the energy industry, it is profoundly threatening to some of the most powerful political interests, who have responded by spending vast sums to discredit it. Historians Naomi Oreskes and Eric Conway have shown that this involve funding the activities of a handful of scientists with an anti-regulatory bent who have attacked not only the climate change consensus, but had also been involved in earlier attacks on scientific research showing the harmful effects of DDT, CFCs, and tobacco. Journalists have also begun to trace the donations of hundreds of millions of dollars from conservative billionaires with fossil fuel industry ties to public relations and lobbying campaigns aimed at attacking the climate change consensus in the media and on Capitol Hill. That a strong consensus supporting the theory of anthropogenic climate change remains despite decades of well-funded, systematic attack enhances its credibility.
While I in no way intend to dismiss research in the Alzheimer’s field over the past several decades that has produced much important knowledge about some of the likely pathological mechanism that lead to dementia, a consideration of socio-historical factors raises questions that are not often enough asked, especially in media coverage. First, while there is no credible denial that age-associated progressive dementia exists as a significant individual and social problem, there are many different theories regarding what causes it among respected researchers in the field, and debate within the field about whether it can truly be disentangled from usually more benign processes of systemic brain aging. Second, while researchers from diverse fields certainly conduct Alzheimer’s research, the dominant approach emphasizing the drive to pharmacological treatment and prevention is the product mostly of psychiatrists and neurologists, and this group is largely supported by a narrow funding stream from the pharmaceutical industry. Critics like David Healy, Carl Elliott, John Abramson and others have documented the distorting effects of pharma money on medical research in general, and several authors in a book on dementia treatment I co-edited show that this happens in the Alzheimer’s field as well. Finally, unlike climate change, the dominant approach to Alzheimer’s disease is in sync with the interests of the pharmaceutical industry, which has accordingly spent vast sums to persuade the public and lawmakers of its importance to society so that there has been relatively little public debate about it. None of this amounts to a reason to dismiss mainstream Alzheimer’s research outright, but it does suggest there is a need to ask some critical questions.
Both climate change and Alzheimer’s disease are complicated problems, and much will no doubt continue to change in the scientific understandings of both of them. But the persistence of such a strong scientific consensus around the fundamental of climate change despite factors that we would normally except to weaken that consensus, especially the strong resistance of powerful economic interests, helps convince me that it is time to take strong steps as a society to lower carbon emissions. While we must also continue to take the challenge of Alzheimer’s disease very seriously, I see a need for a broader debate about whether the emphasis on developing a pharmaceutical solution – which has been promoted by powerful economic interests – has led us to pay too little attention to other ways of effectively responding.
And beyond both of these issues, we need to move beyond ubiquitous claims of scientific authority and superficial controversy to a more thoughtful public discourse about science and its place in society.