When I was in my twenties, I knew a few adepts of Zen Buddhism who would mention the famous koan: “the sound of one hand clapping.” When I asked what it meant, they would usually give me a disdainful look, as if I were too unenlightened to understand. In my view clapping requires two hands—duh!—but maybe I’m wrong because in China now you can “clap” with one finger. An app enables you to clap by tapping your mobile phone.

The Wall Street Journal recently reported that many Chinese citizens tapped their mobile phones to “clap” for snippets of wisdom expressed by Chinese leader Xi Jinping in his three-and-a-half-hour speech to the 19th Communist Party Congress. One person tapped out 1,489 claps in 19 seconds (he used five fingers), putting him in the 99th percentile of the tap-clappers.