Just think: after only one bite, we know if a piecrust is cooked to just the right crisp; we can gauge the level of texture of that tuna steak; and we can sense the doughiness of our favorite bread. We sense this through our teeth, which have a rich network of sensory nerves, opening the brain to an exquisite aesthetic experience. Our enamel has no nerves, but it delivers the vibrations during a chew to the nerves within our teeth, which paint a wonderful sensation of touch in each of our mouths.
Taste and smell help us love food, but let’s not forget chewing. While that last bite may be voluntary, it originates our human instinct to chew, which begins shortly after birth.
At four months old, infants begin gnawing and drooling constantly. As newborns, they were content to suck and swallow their milk. Then suddenly, those very same suckling infants begin to attack everything—with their mouth. They appear desperate to gnaw, and soak shirts and bibs alike in drool.
Parents usually blame this behavior on a tooth about to cut through the gums. They have been told that the discomfort of teething is relieved by gnawing on something and the pain makes the saliva spill. But something much bigger is actually going on, something that will define a part of each of us the rest of our lives: the emergence of the chewing instinct.
All of us start gnawing and drooling with a striking precision at four months of age, usually several months before a first tooth appears, in part because this is the time when we start eating solid foods. And once the chewing instinct is activated, it drives us for the rest of our lives.
As we get older, we get better at hiding this drive, but it is there. We may not drool or gnaw, but we feel the same urgency to chew as the infant. If by injury or illness we are forced not to chew, then the intensity of our drive to chew is made abundantly clear. In most of these situations, even though patients get all their nutrition via liquids, a significant depression can set in from lack of chewing.
So, the next time you’re in the company of an infant, watch in wonder when they begin to gnaw, chew, and drool. One of life’s great pleasures is about to appear. Don’t look down on their messy ways, for now that infant has become one of us—driven to chew.