One day, Kipling Williams, a social scientist, was walking his dog in the park. As he was strolling along, a Frisbee fell at his feet. He picked it up and tossed back to one of the guys who’d been playing with it. Grinning, the guy tossed it back to him, and Williams found himself in the middle of an impromptu triangle toss. Back and forth they went a few times, but then the two friends who had been playing together before he stumble across their path stopped throwing the Frisbee to him and went back to throwing it to each other. Williams felt bereft and excluded.

—Dan Ariely, Misbelief, Harper Collins 2023