Flipping the king and finding a bird is affirming the antecedent flipping the moose and finding something other than the king is denying the consequent. The reason has to do with the way hypotheticals ( if-then statements) work: to make it true you either affirm the antecedent (the “if” statement) or deny the consequent (the “then” statement). When most people are given this question, they will say to flip over the king or maybe the king and the duck, even though the correct answer is the king and the moose. Which of the coins do you have to turn over to determine whether the rule has been violated? Now consider a simple if-then rule: “If a coin has a king on one side, then it has a bird on the other.” Here are four coins, displaying a king, a queen, a moose, and a duck. Suppose the coinage of a country has a portrait of one its eminent sovereigns on one side and a specimen of its magnificent fauna on the other. When a logic puzzle like the following is posed, for example, people get it wrong:

The issue, Pinker argues, is that when behavioral economists like Daniel Kahneman and Amos Tversky conclude that humans are hopelessly irrational, this is because the questions asked in their experiments do not appeal to the sorts of intuitions that our hunter-gatherer ancestors would have come across. In the first chapter Pinker essentially lays out what I take to be his overarching thesis: humans are not irrational (at least not in the way most people would accuse them of being), but in fact many of the things that appear irrational are actually quite rational. It’s difficult to find treatments of these subjects – formal logic, Bayesian probability, game theory, and so on – that are both comprehensive while not being overly complicated. Indeed, anyone who wishes for a clear, concise, and brief course on rationality should read this book, particularly chapters three through nine.

I find little to disagree with in the bulk of the book, particularly the first nine chapters. His newest book, Rationality: What It Is, Why It Seems Scarce, Why It Matters, is another treatise in the vein of Enlightenment optimism.

I genuinely enjoy reading his work, even though his optimism clashes with my pessimism. Steven Pinker is a great public intellectual and proponent of Enlightenment thinking. Rationality: What It Is, Why It Seems Scarce, Why It Matters by Steven Pinker Viking (September 28, 2021) 432 pages

Steven pinker rationality book