How farming changed the human smile — and the way we speak

Next time, when someone compliments your smile, maybe thank the farmers, instead of your parents! Wondering what farmers have to do with your smile. Well, not just your smile, even how you pronounce certain words. Blame the farmers and soft food, if you don’t like the F-word.
When humans switched from tough, fibrous foods to processed grains and softer meals after the rise of agriculture, it changed more than just their diet. This shift also reshaped jaws, resulting in overbites.
When we shifted to processed foods they put less wear and tear on teeth giving adults the overbites normal in children.

According to a new study from the University of Zurich, this shift played a major role in language evolution. The researchers found that farming societies developed labiodental sounds, made by touching the lower lip to the upper teeth, at much higher rates than hunter-gatherer groups.
It was linguist Charles Hockett, who first proposed that hunter-gatherer languages lacked labiodentals because their tougher diets required more chewing. This force on the jawbone led to an edge-to-edge bite where the upper and lower teeth met directly. That alignment made it harder to produce sounds like ‘f’ and ‘v’. Hockett proposed this in 1985.

A team led by linguists Damián Blasi and Steven Moran tested this theory. Using computer models, they found that pronouncing labiodental sounds required 29% less effort with an overbite than with an edge-to-edge bite. They also uncovered an interesting detail that hunter-gatherer languages have only about one-fourth as many labiodentals as farming languages.

The overbites may also have unknowingly led to labiodental sounds in spoken language. As more people in farming communities developed overbites, they naturally began to use these sounds more often. Over time, ‘f’ and ‘v’ became common across Europe and Asia.

For instance, the Proto-Indo-European word ‘patēr’ evolved into ‘faeder’ in Old English, about 1500 years ago. Labiodental sounds comprise 76% of Indo-European languages today.
Back in the day, in India and Rome, labiodentals may have even been a sign of status, indicating a diet rich in processed foods, something associated with wealth!

Though the labiodental sounds have contributed to speech and human communication, it also comes with certain drawbacks. The shift to a softer diet led to shorter lower jaws, resulting in wisdom teeth, and more dental crowding.
(Pic courtesy: iStock)