The conventional explanation for controversy over climate change emphasizes impediments to public understanding: limited popular knowledge of science, the inability of ordinary citizens to assess technical information, and the resulting widespread use of unreliable cognitive heuristics to assess risk. A large survey of U.S. adults (N = 1540) found little support for this account. On the whole, the most scientifically literate and numerate subjects were slightly less likely, not more, to see climate change as a serious threat than the least scientifically literate and numerate ones. More importantly, greater scientific literacy and numeracy were associated with greater cultural polarization: respondents predisposed by their values to dismiss climate change evidence became more dismissive, and those predisposed by their values to credit such evidence more concerned, as science literacy and numeracy increased. We suggest that this evidence reflects a conflict between two levels of rationality: the individual level, which is characterized by the citizens’ effective use of their knowledge and reasoning capacities to form risk perceptions that express their cultural commitments; and the collective level, which is characterized by citizens’ failure to converge on the best available scientific evidence on how to promote their common welfare. Dispelling this “tragedy of the risk-perception commons,” we argue, should be understood as the central aim of the science of science communication.
Having read through the article, I find myself in a love-hate relationship with it. On the one hand, the study gets the big picture right. The empirical evidence that increased scientific literacy and numeracy leads to increased polarization over the reality of global warming rather than increased consensus, it is a devastating critique of the deficit model. Moreover, I agree with their emphasis on the importance of values.
But the paper goes seriously off track in its understanding of the dynamics of public opinion. At the individual level, the paper treats each individual as a little philosopher, rationally organizing their world into a coherent scheme. This is the same basic presumption that animates the deficit model. Except the proponents of the deficit model presume the existence of a universal rationality (science), leading to the presumption that greater scientific literacy will result in enlightenment. In place of a universal rationality, Kahan and his co-authors have substituted culturally specific (and, thus, not universal) rationalities tied to particular values. Everyone is still 'rational' and living in a world that is intersubjectively coherent and consistent, it is just that the shared consensus is within a particular group (people who share the same values) rather than the public as a whole.
This is true, and a big improvement on the standard story, to a point. The problem is they presume every individual is a little philosopher when the evidence is that only about 15-20% of the population is 'rational' in the sense of holding an ideologically coherent view of the world. Admittedly, this small slice of the public is disproportionately important because they tend to frame the terms of the debate. But in a democracy, where everyone's opinion counts, it is a mistake to treat all public opinion as a projection of the dynamics associated with the ideological minority. And this is precisely what Kahan and his colleagues, with their argument about the 'tragedy of the risk perceptions commons,' do.
Think, for example, of the classic culture war issue: the abortion debate. On the one hand you have a view that is ideologically coherent and privileges life. These people see abortion as murder and are opposed to all abortions. On the other hand, you have an ideologically coherent view that privileges women's control over her body and, hence, the right to choose an abortion if she wishes. On the face of it, this scenario conforms very well with the dynamics Kahan and his colleagues describe. You have two separate cultural value systems, each rational in their own way, and a debate framed in terms of the two conflicting cultural values.
But the vast majority of individuals do not hold ideologically pure and consistent views -- that abortion is always wrong or that it is always a choice to be made by the woman. The bulk of individuals have contingent and contextually specific views: abortion is wrong, but there are exceptions for rape or the health of the mother; abortion is a women's choice but she shouldn't choose an abortion for purely economic reasons, etc.
The little philosopher model of human thought argues that people have a coherent set of consistently prioritized values: a > b > c > d > e. Thus, they will choose a over c but prefer c to d. But, as the abortion example shows, this isn't the best way to conceptualize public opinion. The vast majority of people do not think in these terms. For most people, context and the specifics of the situation matter more than abstract principals.
Simply put, the cultural war model is a big improvement on the deficit model. But the culture war model has a significant problem of its own. It represents the public as divided into two mutually exclusive groups based on competing value schemes. A more accurate representation sees the public as divided into three groups rather than two: the two ideological factions who, despite being a numerical minority, dominate the debate and a third group, the bulk of the public who conceptualize the world in situational and contextual specifics rather than ideological absolutes and are increasingly disenchanted with the polarization of political discourse. Moving away from the deficit model is a good first step. But substituting the culture war model isn't the answer. We need a model of political discourse that doesn't presume everyone is a little philosopher.