The word according to Adam
Adam Kendon and I disagree on just one aspect of the role of gesture in language evolution. Where I propose that manual gesture preceded speech, he argues that gesture and vocal language evolved as equal partners. Some arguments for the gesture-first theory no longer seem to carry force, but the main support comes from evidence that vocal production in nonhuman primates is largely involuntary and inflexible, whereas manual action is flexible, intentional and learnable. This suggests that language evolved from manual grasping and manipulation in primates to pantomime in our hominin forebears, and was gradually conventionalized toward arbitrary symbols. Speech was one outcome of this process, although gesture is an option, as in signed languages, and also accompanies spoken discourse.