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LATE-BREAKING NEWS AND NOTES FROM THE WORLD OF ARCHAEOLOGY
T
ry saying “f ” and “v” and pay close attention
to your lower lip and upper teeth. Would it
surprise you to learn that these sounds are
relatively recent additions to human languages?
Languages, of course, develop over time as usage,
meaning, and pronunciation change. But what
about the ways our bodies have changed over
the millennia? Could this also contribute to
changes in language? In a new study, researchers
from the Max Planck Institute for the Science
of Human History and the University of Zurich
have used evidence from paleoanthropology,
speech biomechanics, ethnography, and
historical linguistics to determine that, in fact,
it is a combination of factors—both cultural and
biological—that produces changes in language
and has contributed to the diversity of languages
that exist today.
In the Neolithic period, starting about 10 , 000
years ago, when the lifestyle of people in Europe
and Asia changed dramatically as a result of the large-scale
adoption of farming in place of hunting and gathering, their
biology changed, too. Prior to this shift, the consumption of
gritty, fibrous foods such as nuts and seeds, staples of the pre-
Neolithic diet, put a great deal of force on children’s growing
mandibles and wore down their molars. In response to the
biomechanical stress of chewing these tough foods, people’s
jawbones grew larger and larger over their lifetimes, and their
molars drifted toward the front of the mouth, eliminating
their childhood overbites. With the development of farming,
easily chewable foods such as processed dairy products and
milled grains were introduced intopeople’s diets. As the
prevalence of these foods increased, people began to retain
their childhood overbites well into adulthood.
In the 1980 s, a linguist named Charles Hockett proposed
that this physical change helped lead to a change in the sorts
of sounds included in languages, but his theory gained little
traction. The current team, led by linguists Damián Blasi
and Steven Moran, set out to test Hockett’s theory. They
anticipated finding that he had been incorrect. The team used
computer models of jaws and teeth exhibiting different bite
patterns to investigate the linguistic consequences of the moveto a diet of softer foods. Specifically, they wanted to test the
implications of an extended overbite against the pre-Neolithic
edge-to-edge bite. “I think that we largely use this idealized
notion of humans as coming with a fixed, uniform biological
profile, which is a reasonable starting point,” Blasi says. “But
the copious evidence for human adaptation at the biological
level to different diets, behaviors, and ecologies needs to be
considered more seriously if we want to have an integral view
of the factors shaping the structure of languages.”
Blasi, Moran, and their team demonstrated, to their
surprise, that how a person’s teeth align can lead to
significant differences in the sounds they tend to make.
Most importantly for their study, they showed that people
with retained overbites could more easily articulate a range
of consonants called labiodentals—produced when the lower
lip comes into contact with the upper teeth. Examples of
labiodentals include “f ” and “v.” An overbite, they found,
enables people to make these sounds with 29 percent less
muscular effort than doing so with an edge-to-edge bite.
At the same time, an overbite makes it harder to produce
bilabials, such as “b” and “p,” which require the lips to
be pressed together. As a result, these sounds frequentlyYOU SAY WHAT YOU EAT
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Edge-to-edge bite,
Upper Paleolithic skull,
Arene Candide Cave, Italy