Our ability to talk with our hands came from...fish?
New research from Cornell University concludes that the evolutionary origin of people using their hands while talking may be linked to the caudal hindbrain of fish. Lead researcher Andrew Bass noted that fish brains have a compartment that allows them to vocalize and gesture with their pectoral fins simultaneously. Humans use the same part of the brain for both talking and hand gesturing, he said.
For the study, the scientists looked at how the brain is connected to different muscle groups. They mapped the early development of the two systems in the brain that control the muscles enabling fish to vocalize and move their pectoral fins. And they determined that both systems arise from the same compartment in the brain.
There already is considerable research showing a connection between speech and gesturing in humans. One example: Blind people still gesture with their hands while talking.