AUDITORY LATERALIZATION IN MONOZYGOTIC TW INS - AN INVESTIGATION WITHTHE DICHOTIC CONSONANT-VOWEL RECALL TEST

Auditory lateralization was examined in 21 monozygotic twin pairs (n = 42) and 52 singletons (healthy volunteers). Nine of the twin pairs we re discordant for handedness, and 12 consisted of concordantly right-h anded persons. All subjects were studied with a German dichotic conson ant-vowel recall test using the syllables /ka/, /ta/, /pa/, /ga/, /da/ and /ba/ as stimuli. There was (i) a marked right-ear advantage in ri ght handed singletons (as expected), (ii) no significant ear advantage among monozygotic twins (neither among those concordant nor those dis cordant for handedness), and (iii) no relation between the direction o f ear advantage within twin pairs. These data suggest that auditory la teralization is largely determined nongenetically.