Eating habits and food processing skills from two million years ago helped us to develop language. Researchers say that cutting up meat was a crucial step in our evolution. We needed less time for chewing, which gave us more time to develop language and communicate. Cutting up food saved early humans as many as 2.5 million chews per year. In contrast, chimpanzees spend half their day chewing. This means they have less time to communicate.
Researchers also say the shape of our face changed. Our jaws and teeth became smaller. A professor said: "We went from having…big teeth…to having smaller teeth." He said this, "allowed for the selection for speech and other shifts in the head, like bigger brains." The professor chewed raw meat to test his theory. He said: "You chew and you chew and you chew, and nothing happens." He said that slicing meat, "is the simplest technology of all".