Visual decentration: from stereometric points to planeometric forms.

19 3-yr.-olds chose to put blocks together to produce good continuation across stereometric edges. 4 mo. later they began to produce good continuation across planeometric edges. A group of 15 4-yr.-olds chose to produce symmetrical forms rather than simply to align edges. Symmetrical form was produced across planeometric surfaces but not across stereometric contours. These data suggest that visual decentration is first a shift from looking at single points touched to single points displaced from touch and, at a still later age, a shift to the organization of many points. The failure of the older group to produce a symmetrical form across stereometric contours could have resulted from the cultural press to attend to planeometric information.