“All Cretans are Liars”: The Epimenides Paradox

Scientific studies show that political biases consistently thwart rationality when examining data.

Our biases often make us incapable of rational analysis (RHT).

In the study of logic, the Epimenides paradox, sometimes called the liar’s paradox, is the statement of a liar who affirms that he is lying.

The paradox, named after the Cretan philosopher Epimenides (circa 600 BC) goes something like this: Epimenides announces that “all Cretans are liars” but, he is himself a Cretan, therefore he is a liar. And, since he is a liar, his assertion must be untrue, consequently all Cretans are truthful.

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Social scientist often used the liar’s paradox to illustrate the problem of self-reference in which we process information according to our biases. We ought to be rational, but we fall short of rationality. We consume information, not to enhance the accuracy of our opinions, but to reinforce our beliefs. This phenomenon is in full display in the political opinions expressed by columnists and media commentators.

We are self-deceived, and quite wrong about the depth of our understanding of the world. If we were to ask a random sample of people if they understand how their wristwatch works, most would respond that they do. But if we ask them for a detailed explanation of how exactly a wristwatch tells time, we are unlikely to get a thorough answer. Social scientists call this bias the Illusion of Explanatory Depth. “Most people feel they understand the world with far greater detail, coherence, and depth than they usually do” (Rozenblit and Keil). In my Cuban slang, “se la saben todas” (they know it all).

Surveys confirm that most Americans limit their readings to distilled sources and headlines. When asked for detailed explanations of say, government spending, self-knowledge drops dramatically. Our consumption of knowledge is not deep. And the most overconfident pundits are often among the most ignorant, who never feel they have to inform themselves or justify their arguments. Social psychologist David Dunning has shown that; the lowest performers on tests of logical reasoning are the most likely to overestimate their test scores.

Dan Kahan, Professor of Law at Yale, and his colleagues have done fascinating work showing how our political views corrupt our reasoning. In one study, individuals were assessed in advance as to their political views and mathematical reasoning ability. The participants were then asked to solve a problem that required interpreting the results of a fake scientific study.

In reality, there were two fake studies with the same numerical data. One study was described as measuring the effectiveness of a new cream for treating skin rashes. The other study was described as a law banning carrying concealed weapons in public. Keep in mind, that both studies were identical in data and results. Both studies presented the same information; the only difference was the description of the subject matter of the study.

The participants analyzing the “skin cream” data showed no difference in their analysis whether they were Democrats or Republicans. They were unbiased in their interpretation of the data. In contrast, the participants that analyzed the “gun-control” data diverged from each other according to their personal politics. Interestingly, the more mathematically sophisticated respondents, Republicans or Democrats, showed the greater biases.

Professor Kahan offers that when participants sensed that an answer was contrary to their ideological views, they scrutinized the data further trying to figure out another way of understanding it. When the answer was politically convenient, it felt right, and required no further investigation. Psychologists have shown that we direct reasoning toward a preferred conclusion rather than following the data to wherever it may lead us. This is the case with many columnists and commentators.

Politically, we always see more shortcomings in the other side. The titles of two articles discussing Dr. Kahan’s work make the point: “How Politics Makes Us Stupid” (E. Klein), and “Science Confirms: Politics Wrecks Your Ability to Do Math” (C. Mooney).

Kahan’s work shows that our political biases skew our reasoning therefore; we should not treat our partisan preferences as unassailable philosophical values. Our partisan preferences are hypotheses to be tested over time. We need a political culture of reason. One that does not consider all Cretans to be either liars or truthful.

Dr. Azel‘s latest book is “Reflections on Freedom.”

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