Everyday, we participate in seemingly arbitrary but essential choices for society to function. We all agree on what side of the road to drive on, to use paper currency, or to speak the same language. These kinds of choices make up a group’s common knowledge – things that are made blatantly and publicly known. But what about the things that are known, but unspoken? What is the purpose of innuendos, euphemisms, and veiling the true meaning of our words in society? Steven Pinker, an experimental psychologist and Harvard professor, joins hosts and finance professors Jonathan Berk and Jules van Binsbergen to discuss his new book When Everyone Knows That Everyone Knows: Common Knowledge and the Mysteries of Money, Power, and Everyday Life. In this two-part conversation, they explore the psychological and social significance of common knowledge in human interactions, highlighting its complex role in both fostering cooperation and permitting social taboos. They also discuss the intersection of common knowledge with economic behaviors like speculative trading, and the balance between maintaining social norms and fostering open debate in academic settings. Find All Else Equal on the web: https://lauder.wharton.upenn.edu/allelse/ All Else Equal: Making Better Decisions Podcast is a production of the UPenn Wharton Lauder Institute through University FM.