Perceptions of authority, meanwhile, appeared to come from the scale of vertical movements – whether your hand sweeps from the level of the lectern, say, to shoulder height. People who regularly make these kinds of expansive gestures tend to be rated as being less agreeable, but more dominant. “It is a very consistent result, across many papers of mine,” Koppensteiner says.
In one particularly striking article from 2015, Koppensteiner found that these personality ratings, based solely on the silent animations of stick men, could predict the amount of applause the politicians actually received in the real-life speeches that the animations had been drawn from.
There was a catch, however, since those rating also predicted whether the politicians were heckled – suggesting that the gestures of dominance can be perceived as positive or negative depending on the context. Perhaps, in the wrong circumstances, gestures of dominance can also be seen as arrogant, aggressive, or overbearing.
Besides altering the perceptions dominance, the expansive vertical hand movements also altered estimates of the speaker’s physical height. “People were mostly impressed by the real height of the stick figures, but if they moved their arms up and down vigorously, and with lots of expansive arm movements, you seem to be judged as being taller,” he says.
The exact psychological mechanism is not clear. Since previous research had shown that taller people are naturally considered to be better leaders, it’s possible that the movements create a kind of visual illusion to increase your perceived height, and this then contributes to perceptions of greater dominance. But it could also work in the opposite direction: the increased dominance leads to the altered perceptions of height.
“We know that if people are in high-status positions, they are seen as being taller,” Koppensteiner says. As he points out, people often overestimate Tom Cruise’s height, and although that could be due to clever camera work, it could also come from the way he projects his confidence.