HEMISPHERIC-SPECIALIZATION IN CHILDREN AS REFLECTED IN THE LONGITUDINAL DEVELOPMENT OF EAR ASYMMETRY

The longitudinal development of ear asymmetry was investigated in 2 samples of kindergarten and primary school children over an age range of 6 yr. Ear preference in a dichotic digit test, administered 4 times, did not appear to be affected by age and sex: right ear advantage was predominant at all times. Individual comparisons showed the development of ear advantage to depend on initial preference. Initially left eared subjects when changing ear advantage do so from left to right at early and from right to left at later school ages. The left-right shift may be due to the school teaching of linguistic skills which could selectively activate the left cerebral hemisphere. This explanation is supported by the finding that initially right eared subjects tended to conserve that preference at early school ages.