Algorithms to Live By: The Computer Science of Human Decisions

by Brian Christian

Understanding the exact function and meaning of human backchannels continues to be an active area of research. In 2014, for instance, UC Santa Cruz’s Jackson Tolins and Jean Fox Tree demonstrated that those inconspicuous “uh-huhs” and “yeahs” and “hmms” and “ohs” that pepper our speech perform distinct, precise roles in regulating the flow of information from speaker to listener—both its rate and level of detail. Indeed, they are every bit as critical as ACKs are in TCP. Says Tolins, “Really, while some people may be worse than others, ‘bad storytellers’ can at least partly blame their audience.” This realization has had the unexpected side effect of taking off some of the pressure when he gives lectures—including, of course, lectures about that very result. “Whenever I give these backchannel talks, I always tell the audience that the way they are backchanneling to my talk right now is changing what I say,” he jokes, “so they’re responsible for how well I do.”