Since vocal distinctive features (sound contrasts) are ideal for this purpose, it was only at this point—when intrinsically persuasive body-language was no longer required to convey each message—that the decisive shift from manual gesture to our current primary reliance on spoken language occurred.
S obzirom da su distinktivne osobine glasa (zvukovni kontrasti) idealni za tu svrhu, tek se u tom trenutku - kada intrinzično ubedljivi govor tela nije više bio potreban da bi se prenela svaka poruka - desio konačni prelazak od manuelnih gestova na naše današnje primarno oslanjanje na govorni jezik.