A new study claims to provide ‘some of the strongest evidence yet’ for the benefits of gesturing to help students learn.
The study involved 184 children aged 7-10, of whom half were shown videos of an instructor teaching math problems using only speech, while the rest were shown videos of the instructor teaching the same problems using both speech and gestures. The problem involved mathematical equivalence (i.e., 4+5+7=__+7), which is known to be critical to later algebraic learning.
Students who learned from the gesture videos performed substantially better on a test given immediately afterward than those who learned from the speech-only video (average proportion correct around 42% vs 31% — approximations because I’m eyeballing the graph), and, unlike the speech-only group, showed further improvement on a test 24 hours later (around 46% vs 30%). They also showed stronger transfer to different problem types (35% vs 22%).
 Consolidation and Transfer of Learning After Observing Hand Gesture. Child Development. n/a - n/a.(2013).