human non human language bear question primate language skill observation appear imitate manner something controvert monkey monkey clue why culture language primate national geographic series primate research few week ago show chimp stick poke through hole beehive suck off honey introduce topic tool next segment researcher candy table surround sort cage vertical bar primitive kind rake three widespace tine rest table handle through bar chimp same adjacent section table tine down nt candy widespace tine nt retain researcher demonstrate flip rake over back rake table top easy pull candy one s hand matter often chimp nt inference experiment primate perceive tool accomplish end attend manner tool next segment similar setup small child child fail tine down adult demonstrate flip rake over child immediately next turn same even move rake through curve path much execute adult s rake capture object block pull back edge support hypothesis believe observation cultural difference between one community primate another comparable difference human body language style linguistic dialect difference manner same thing functionally inconsequential difference thing same thing bruce nevin bn lightstream com 