New research shows its incredibly easy for people watching others shake boxes to tell what they're up to. Just as they might be able to tell what's inside the box by shaking it around, you can tell what they are trying to figure out when they shake it." Video credit: Johns Hopkins UniversityIn a series of experiments, the researchers asked hundreds of people to watch others shake boxes. "When we present this work we always talk about Christmas presents," Firestone said. Multimedia available: The GIF of a present-shaking child used here, as well as matching video clips and stills are available.