Out of the mouths of primates, facial mechanics of human speech
may have evolved Posted June 20, 2012; 09:00 a.m. Princeton
researcher explains link from friendly primate facial gesture to
human speech The throat and facial movements that twist the air
pushing through your vocal cords into words could be rooted in
the well-meaning expressions primates exchange with each other,
according to two recent studies based at Princeton University.
The researchers found that the oral-facial component of human
speech mirrors the rhythm, development and internal dynamics of
lip smacking, a friendly back-and-forth gesture performed by
primates such as chimpanzees, baboons and macaques. The studies
also show that the mechanics of primate lip smacking are
distinct from those of chewing, similar to the separate
mechanics of human speech and chewing. These parallels suggest
that in primates chewing and lip smacking — as with chewing and
speech-related facial movement in humans — have separate neural
controls, explained Asif G