Truth DecayEnough with the Quackery, Pinker Says

By Colleen Walsh

Published 14 October 2021

“Another contributor [to the opposition to vaccines] is the Myside bias, probably the most powerful of all the cognitive biases, namely, if something becomes an article of faith within your own coalition, and if promoting it earns you status, that is what you believe,” says Harvard’s professor of psychology Steven Pinker, whose latest book — Rationality: What It Is, Why It Seems Scarce, Why It Matters – has just been published. “It’s somewhat arbitrary which positions get attached to which coalitions…. It used to be the tree-hugging Mr. and Ms. Naturals who were suspicious of vaccines — a romantic opposition to science and tech made vaccine resistance a leftish cause. But now it’s more attached to the right. In either case, people are more adamant about protecting the sacred beliefs of their political tribe than looking at the best evidence.”

At a time when belief in science appears to be waning, conspiracy theories seem to be on the rise, and many Americans cannot agree on basic facts, Steven Pinker argues for a return to rational thought and public discourse in his latest book, Rationality: What It Is, Why It Seems Scarce, Why It Matters. Pinker, Harvard’s Johnstone Family Professor of Psychology, and author of The Better Angels of Our Nature: Why Violence Has Declined, and Enlightenment Now: The Case for Reason, Science, Humanism, and Progress, thinks “we will always need to push back against our own irrationality,” and that education, democracy, science, and journalism, along with an awareness of our own biases, can help us embrace a more rational approach to everyday issues.

Pinker spoke with the Harvard Gazette’s Colleen Walsh.

Colleen Walsh: Can you define rationality in a sentence?
Steven Pinker
: I define it as the use of knowledge to attain a goal, where “knowledge,” according to the standard philosopher’s definition, is “justified true belief.”

Walsh: We see examples of seemingly irrational beliefs and behaviors every day, but you argue that people are fully capable of being rational. How do you explain that disconnect?
: First, rationality is always in pursuit of a goal. Sometimes that goal is rational for each of us as individuals but irrational for us as a society — a tragedy of the rationality commons, as when it makes sense for every shepherd to graze his sheep on the town commons, but when everyone does it, the commons gets denuded and they’re all worse off. In this case, if everyone is ingenious in gaining prestige within their political sect by glorifying its sacred beliefs and demonizing rival sects, that may work to everyone’s individual advantage, but not to the advantage of the whole society in its interest in the truth and the best policies.