The Extended Mind: The Power of Thinking Outside the Brain

by Annie Murphy Paul

Yet the most popular and widely viewed instructional videos available online largely fail to leverage the power of gesture, according to a team of psychologists from UCLA and California State University, Los Angeles. The researchers examined the top one hundred videos on YouTube devoted to explaining the concept of standard deviation, an important topic in the study of statistics. In 68 percent of these recordings, they report, the instructor’s hands were not even visible. In the remaining videos, instructors mostly used their hands to point or to make emphatic “beat” gestures. They employed symbolic gestures—the type of gesture that is especially helpful in conveying abstract concepts—in fewer than 10 percent of the videos reviewed.