As the cliché goes, people don’t always practice what they preach—particularly in some professions. Take the police: when Florida’s Sun Sentinel examined the records of 3,915 officers who had traveled on toll roads in 2011, the paper found that nearly 800 of them had driven at speeds of 90 to 130 miles an hour, many either while off duty or in violation of department rules that barred excessive speeding even in emergencies. Or consider physicians: one study of 500 doctors found 38 percent of them to be overweight, versus 33 percent of American adults (to be fair, the doctors’ rate of obesity was lower) [1]. Or those in retail: according to the security company Checkpoint Systems, the people who steal most from North American stores aren’t shoppers, but employees.

Recently, some philosophers have started spotting ironies in their colleagues’ behavior. Their findings suggest that those who ponder big questions for a living don’t necessarily behave better, or think more clearly, than regular people do. In one study, 573 professors—about a third of them ethicists—were asked about their personal behavior and beliefs. Sixty percent of the ethicists rated eating red meat as “morally bad,” but only 27 percent said they didn’t regularly eat it. Ethicists and political philosophers were no more likely to vote than other kinds of professors, nor were ethicists more likely to donate blood or register as organ donors. “On no issue did ethicists show unequivocally better behavior than the two comparison groups,” the researchers reported [2].

Another study shows ethicists to be especially delinquent library patrons: compared with other philosophy texts, “contemporary ethics books of the sort likely to be borrowed mainly by professors and advanced students of philosophy” were roughly 50 percent more likely to be permanently missing [3].

Philosophers are also vulnerable to biases. For example, one study found that, compared with introverted peers, extroverted experts in philosophy and psychology were more likely to hold certain beliefs about free will [4]. In another study, people with advanced philosophy degrees answered a pair of ethical questions differently depending on which was posed first [5]. And when presented with variations of the trolley problem—a classic Philosophy 101 dilemma that forces a choice between killing one person to save several people from being hit by a trolley, or not committing the murder but letting the people die—philosophers and laypersons alike tended to change their answers depending on the means of murder [6].

Still other researchers are exploring the connections between neuroscience and philosophical belief. For example, one small study found that people with damage to their brain’s prefrontal cortex tended to have “an abnormally ‘utilitarian’ pattern of judgments on moral dilemmas” [7]. Such studies might tell us something about the origins of our convictions, but at least one metaphysical mystery will likely remain: why, compared with everyone else, philosophers seem to be worse about calling their mothers [2].

The Studies:

[1] Bleich et al., “Impact of Physician BMI on Obesity Care and Beliefs” (Obesity, May 2012)

[2] Schwitzgebel and Rust, “The Moral Behavior of Ethics Professors” (Philosophical Psychology, May 2014)

[3] Schwitzgebel, “Do Ethicists Steal More Books?” (Philosophical Psychology, Dec. 2009)

[4] Schulz et al., “Persistent Bias in Expert Judgments About Free Will and Moral Responsibility” (Consciousness and Cognition, Dec. 2011)

[5] Schwitzgebel and Cushman, “Expertise in Moral Reasoning?” (Mind & Language, April 2012)

[6] Greene, “Beyond Point-and-Shoot Morality” (Ethics, July 2014)

[7] Koenigs et al., “Damage to the Prefrontal Cortex Increases Utilitarian Moral Judgements” (Nature, April 2007)