Eating habits and food processing skills from around two million years ago helped humans to evolve and develop language. Researchers from Harvard University say that learning to cut meat up and using basic stone tools to process food were crucial steps in our evolutionary process. The fact that we cut food up or pounded and crushed it meant we needed less time for chewing. This gave our mouths more free time to develop language and communicate. The researchers estimate that cutting up meat and other food saved early humans as many as 2.5 million chews per year. In contrast, the chimpanzee spends half of its day chewing, which means it has less time to communicate.
The researchers also said the shape of our face changed because we needed to chew less. Our jaws and teeth became smaller because we had learnt to cut up food. Professor Daniel Lieberman said: "We went from having snouts and big teeth and large chewing muscles to having smaller teeth, smaller chewing muscles, and snoutless faces. Those changes, and others, allowed for the selection for speech and other shifts in the head, like bigger brains." Dr Lieberman chewed raw goat meat to test his theory. He said: "You chew and you chew and you chew and you chew, and nothing happens." He added that to some extent, slicing meat into smaller pieces before chewing, "is the simplest technology of all".