Acceptance of Science and Ideology

President Barack Obama was born in Hawaii on August 4, 1961. Recent U.S. surveys reveal that only 1 in 3 Republicans accept this simple fact, notwithstanding the incontrovertible evidence provided by something as straightforward as a Hawaiian birth certificate. The remaining 2 out of 3 Republicans either believe that President Obama was born outside the United States (between 45% and 51%, depending on the particular poll) or they profess uncertainty about his place of birth.

What motivates people who, based on Republican demographics likely earn a living in business or dentistry or some other well-paying job requiring at least a modicum of literacy, to overlook the obvious and subscribe to patent absurdities instead?

Last year, the U.S. National Academy of Sciences, America’s highest scientific body, summarized the current state of climate science thus: “Some scientific conclusions or theories have been so thoroughly examined and tested, and supported by so many independent observations and results, that their likelihood of subsequently being found to be wrong is vanishingly small. Such conclusions and theories are then regarded as settled facts. This is the case for the conclusions that the Earth system is warming and that much of this warming is very likely due to human activities.”

Notwithstanding the Academy’s crystal clear statement, recent surveys reveal that the majority of U.S. Republicans do not accept this scientific fact. Climate science is clearly more complex and intricate than a birth certificate, so perhaps this is not altogether surprising. However, complexity alone does not explain why acceptance of the science decreases among Republicans with level of education as well as with their self-reported knowledge: Whereas Democrats who believe they understand global warming better also are more likely to believe that it poses a threat in their lifetimes, among Republicans by contrast, increased belief in understanding global warming is associated with decreased perception of its severity.

What motivates people to reject facts that are so strongly supported by evidence? And why are Republicans more likely to engage in such “denial” than Democrats?

The psychological literature provides some insight into this question.

To begin with, it must be realized that this has nothing to do with the particularities of American politics or some idiosyncratic aspect of the Republican Party itself. The same division of the political spectrum has been observed in other countries such as Canada (Heath & Gifford, 2006) or Australia (Leviston & Walker, 2010). The problem thus runs deeper; it crosses national boundaries but it always reveals a fissure along the left-right continuum of politics. Why?

Numerous studies converge onto the conclusion that there is a strong correlation between a person’s endorsement of unregulated free markets as the solution to society’s needs on the one hand, and rejection of climate science on the other (e.g., Heath & Gifford, 2006; Kahan, 2010). The more “fundamentalist” a person is disposed towards the free market, the more likely they are to be in denial of global warming. This ideological bent can be identified in a number of ways; for example, Heath and Gifford (2006) used a 6-item scale that pertains exclusively to the free market, whereas Kahan and colleagues have worked with a more elaborate scale that picks up people’s “worldviews” across a broader range of issues. Ultimately, the subtle differences between the various instruments pale in comparison to the common denominator: Endorsement of free markets in combination with other streaks of “hierarchical” or “authoritarian” thinking are statistically associated with rejection of climate science.

But why? What do markets have to do with geophysics?

The answer is that global warming, like many other environmental problems, poses a potential threat to laissez-faire business. If emissions must be cut, then markets must be regulated or at least “nudged” towards alternative sources of energy—and any possibility of regulation is considered a threat to the very essence of their worldview by those for whom the free market is sacrosanct. (As an aside, this fear of regulation can actually be counter-productive; there is evidence that regulation can have beneficial effects to the industry being regulated; Farzin, 2003. So rational self-interest is insufficient to explain the fear of regulation).

It is this deep psychological threat that in part explains the hyper-emotionality of the anti-science discourse: the fear of Obama as an alien “other”; frenetic alarmism about a “world government”; the rhetoric of “warmist” or “extremist” leveled at scientists who rely on the peer reviewed literature; the ready invocation of the spectre of “socialism”—they all point to the perception of a threat so fundamental that even crazed beliefs constitute an alluring antidote.

Does this mean that free-market economies are incompatible with action on climate change? Does this mean that irreconcilable differences remain between action on climate change and people with a “free-market” worldview?

Fortunately, the answer is “no” to both questions.

First, mainstream free-market economies embarked on a path towards reducing emissions long ago, and some of the most vigorous proponents of decarbonization of their economies are European leaders from the conservative side of politics, such as Britain’s David Cameron or Germany’s Angela Merkel. Likewise, mainstream free-market outlets such as The Economist have little patience for climate denial but instead focus on moving forward and creating new business opportunities in the clean-energy sector. Finally the peer-reviewed literature in regulatory economics is replete with analyses of the best way forward to cut emissions, further revealing the current wave of climate “skepticism” to be an exercise in misguided futility.

Second, there is evidence from the laboratory that reframing necessary action against climate change (or some other environmental problem) as a business opportunity rather than as a regulatory burden may elicit support for policy measures even from people whose worldview predisposes them towards the free market (Kahan et al., 2007). The fact that this reframing can enable people to support action on a problem whose very existence they would otherwise likely deny offers a path forward from the current impasse.

A related and quite intriguing result arose from a recent survey of some 5000 Australians (Leviston & Walker, 2010). The results showed that although people who identified with the conservative party (called the Liberal Party in Australia) were less likely to accept that humans cause climate change than people affiliated with other parties, they nonetheless held large corporations and industrialized countries responsible for it. In other words, “humans don’t cause climate change but large corporations are responsible.” One interpretation of this slightly illogical position is that public protestations of climate denial do not reflect people’s actual knowledge and acceptance of the science, but simply signal one’s tribal identity to other members of the tribe, as Naomi Klein has recently suggested.


Farzin, Y. H. (2003). The effects of emissions standards on industry. Journal of Regulatory Economics, 24, 315-327.

Heath, Y. & Gifford, R.(2006). Free-market ideology and environmental degradation: The case of belief in global climate change. Environment and Behavior, 38, 48-71.

Kahan, D. M. (2010). Fixing the communications failure. Nature, 463, 296-297.

Kahan, D. M.; Braman, D.; Slovic, P.; Gastil, J. & Cohen, G. L. (2007). The Second National Risk and Culture Study: Making Sense of – and Making Progress In – The American Culture War of Fact. Yale Law School, Public Law Working Paper No. 154.

Leviston, Z. & Walker, I. A. (2010). Baseline survey of Australian attitudes to climate change: Preliminary report. CSIRO (Behavioural Sciences Research Group).