How Can We Account for the Involvement of Hand Movements in Speaking from an Evolutionary Point of View?
Hand movements often observed when a speaker speaks are like practical actions made in relation to objects in a virtual world. It is suggested that this is because speaking is also a kind of virtual practical action and hand actions are a part of this. They are not remnants of a former "gesture language" nor are they done to help the speaker speak. Rather, they are the manual components of a virtualised oral-manual manipulatory system that has descended with modification from the oral-manual coordination that came about with the development of prehensile feeding.