Regardless of the topic, an easy way for politicians to rally support for their cause is to declare that it is ‘common sense.’ The rhetorical appeal is not new, a famous pamphlet by Thomas Paine declared the cause of American independence from British rule to be common sense. Yet the mantra of common sense seems to have accelerated in the Obama era, with Republicans proposing ‘common-sense solutions’ to government deficits and Democrats offering ‘common-sense’ gun control measures. Even though these and other proposals called common sense are politically contentious, the appeal of common sense persists in our political discourse.
In her book, Common Sense: A Political History, historian Sophia Rosenfeld tracks the historical use of the phase in politics. She traces its origins back to England’s Glorious Revolution, through the American Revolution, and up to modern political use, starting with Reagan. Building on this foundation, I would like to explore the sociology and psychology of common sense, thinking about where and why it persists, and considering the logical and cognitive biases that support it.
The challenge of understanding common sense partly arises from the term’s ability to elude any useful definition. Most available definitions merely re-state the phrase through synonyms, such as Wikipedia’s “basic ability to perceive, understand, and judge things that is shared by nearly all people.” In other words, a ‘common sense’ is a ‘shared perception.’ However, this definition cannot explain the political and rhetorical use of the phrase as the political contentiousness of so-called common-sense proposals demonstrates that they are not universally-shared perceptions. Other definitions are similar, occasionally noting the positive connotation of the phrase.
Rosenfeld proposes an alternative, writing in the Washington Post that,
“In its current political form, ‘common sense’ is intended to telegraph two related messages: Ordinary people know better, especially compared with overeducated, smooth-talking experts and insiders. And governing works best when it is rooted in everyday experience.”
This definition draws out three important characteristics of common sense. First, the phrase draws a rhetorical line between those with common sense who agree with the speaker and those without common sense. Second, it blurs the distinction between experience and expertise claiming that experience alone can illuminate the truth. Finally, common sense under this definition is a politically-active phrase, carrying the implication that society should be organized around common sense, including where it conflicts with unintuitive empirical findings.
Under this definition, appeals to common sense appear frequently across the social sciences, including politics, but only in select areas of the natural sciences. I think there are three distinct sociological reasons why this occurs, which I will attempt to illustrate with examples from economics, climate science and astrophysics.
First, social science studies a world that we experience during our everyday life. Very few people have experience with the extreme curvature of space-time around and inside a black hole, so appeals to common sense about the nature of black holes carry little weight. By contrast, most people have direct experience managing a household budget and thus feel confident relying on their personal experience when making pronouncements about governmental budgets.
Even in the natural sciences, areas where people have direct experience see more claims of common sense. Hence claims that the Earth’s climate is not warming, based on experience of seasonal weather shifts. In a narrow sense, these are all arguments by analogy. Thus, the strength of the argument and the truth of the conclusion depends on the strength of the analogy. When the analogy is weak, such as between a household budget and government budget or between weather and climate, the conclusion is weaker. In a broader sense, this is the confusion of experience and expertise that I noted above. These are claims that the world does not have unintuitive features. However, science is often the study of the unintuitive features of the universe, from its occasionally-peculiar geometry to the oddities of human interaction.
Second, areas of science susceptible to appeals to common sense typically face constraints to empirical testing. An important dividing line between science and pseudoscience for many scientists is the criterion of falsifiability, popularized by Karl Popper. Popperian falsifiability states that to be scientific, a theory must provide testable predictions and that empirical evidence contrary to these predictions falsifies the theory itself. Thus, the general theory of relativity is scientific, as it makes testable predictions about the behaviour of light, time, and matter in an accelerating frame, such as when experiencing gravity, and if those predictions were incorrect, the general theory would have been as well. By contrast, astrology is not scientific, even though it makes predictions, because astrologers always rationalize away the failures of these predictions without changing astrology.
Within the social sciences and certain natural sciences, empirical testing is more difficult. This difficulty allows political foes to declare their theories to be pseudoscience, confusing practical impossibility with theoretical impossibility. Often, this occurs because it is impractical or unethical to test the counterfactual situation through a controlled experiment. Suppose we have a hypothesis that post-secondary education boosts lifetime earnings; it would be unethical to randomly select people to be banned from attending university just to test the hypothesis. Likewise, we cannot create an identical second Earth on which to test the greenhouse effect. Although scientists continue improving techniques to overcome these challenges, the practical difficulty of falsifiability leaves them open to criticism.
Finally, these scientific endeavours have immediate political consequences, meaning conflict over them draws on our moral beliefs, not just empirical evidence.
Moral conflicts are difficult because they raise uncomfortable questions about what we value, and why.
By burying the moral conflict underneath a veneer of disagreement about fact, politicians can signal their moral values to their followers without having to engage with potential moral trade-offs.
For example, a politician may claim that lowering taxes on the highest incomes will enable so-called ‘job creators’ to boost employment for everyone. Although the empirical evidence suggests that this claim is untrue, it allows the politician to avoid the challenge of taking a position on the balance between the wealthy’s right to their income and the poor’s right to sufficient income. Likewise, accepting that climate change is occurring means weighing the risk to the environment, human society, and future generations from not acting with the risk to employment, the economy, and incomes from acting. Neither moral dilemma is easy to resolve. Thus, shifting the debate can provide cover, especially when paired with claims that ‘common sense’ tells us the way the empirical facts must be.
Looking more closely, psychology can also help explain the persistent use of appeals to common sense. Humans are susceptible to several cognitive biases and fallacies of reasoning, many of which are relevant to the prevalence of the appeal to common sense.
A major part of the rhetorical value of common sense is that it allows listeners to engage in attribute substitution. This process occurs when an individual replaces a difficult question with an easier one. Many of the situations where speakers invoke common sense are nuanced and difficult to resolve, but people can easily decide that they don’t want to oppose common sense. Thus, by allowing people to make that substitution, speakers can rouse support for an otherwise contentious position.
Appeals to common sense short-circuit our rational thinking because nobody wants to openly oppose it.
The phrase also gains rhetorical strength through the bandwagon effect, a phenomenon where people become more likely to accept a belief if they think other people have already accepted it. By calling a position common sense, politicians create a bandwagon, even when the policy does not actually have popular support. Nevertheless, by framing a position as common sense, people will be more likely to believe the policy is a shared perception about the world and change their own opinions accordingly.
This appeal to popularity also works due to naïve realism and the false consensus effect. Naïve realism is an individual’s tendency to believe that they see the world objectively and attribute disagreement to irrationality, ignorance, or bias. The false consensus effect leads people to over-emphasize the degree to which one’s opinions, beliefs, and values are typical and are shared by others.
Per sociologist Duncan Watts, our personal common sense is not:
“A scientific theory of the world. Rather it is a hodge-podge of accumulated advice, experiences, aphorisms, norms, received wisdom, inherited beliefs, and introspection that is neither coherent nor even internally self-consistent.”
Not only do we believe that our perception of the world is accurate to the true nature of reality due to naïve realism, but we also believe that other rational people share our views due to false consensus, and dismiss those who disagree as irrational or biased.
Unlike scientific theories, which can be falsified, the breadth of received wisdom provides enough tools that any outcome can be rationalized. If a married couple have similar personalities, then birds of a feather flock together, but if they differ, then opposites attract. If a large team succeeds, then two heads are better than one, but if the team fails, then too many cooks spoil the broth. This breadth allows common sense to manifest itself as the hindsight bias, the tendency to see past events as predictable. Since people rarely need to consider the counterfactual situation — what could have happened — their rationalization survives a cursory examination.
Finally, appeals to common sense trigger the in-group bias, a tendency where people automatically view members of ‘their’ group more favourably than outsiders, even if the groups are arbitrary. Per Rosenfeld’s description of common sense, these appeals draw on anti-intellectualism to delineate ‘ordinary people with common sense’ from ‘out-of-touch elites.’ As speakers frequently use common sense to dispute scientific findings, this rhetoric redefines the so-called elites’ use of empirical data from a means to support a premise into a way for them to denigrate their opponents. Then, in-group bias causes listeners to oppose the scientific finding to defend their imagined in-group without engaging with the underlying data.
To quote Rosenfeld once more,
“The political appeal to common sense is thus best understood not as a call for clearheaded solutions, but rather as a form of pandering… [lathering] voters with collective flattery.”
From both sociological and psychological perspectives, our biases and fallacies of reasoning permit common sense to persist in our political discourse. Even worse, our bias to see ourselves as consistent and rational impair our ability to see these biases and reduce their warping effect on our thinking. Yet per psychologist Daniel Kahneman, choosing to engage in deliberate, effortful thinking can reduce the impact of cognitive bias. Thus, we should endeavour to think clearly and deliberately and by doing so, expel common sense from our political vocabulary.
