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".