Figure 2.
Mean handedness score for chimpanzees as a function of consistency in gesture type. Group 1 = use of food begs on all three trials. Group 2 = use of a food beg on two trials and a point on one trial. Group 3 = use of a food beg on one trials and a point on two trials. Group 4 = use of a point on all three trials. A mean handedness score of 1.0 reflects exclusive right hand use and a score of −1.0 reflects exclusive left hand use. Values between −1.0 and 1.0 reflect mixed hand use.