Auditory lateralization in monozygotic twins.

In an attempt to investigate whether auditory lateralization has a heritable component, 20 monozygotic (MZ) twin pairs were examined with four different dichotic listening tests known to produce reliable right-ear advantages (REAs) in right-handers. Ten twin pairs were concordantly right-handed (MZ-RR), and ten twin pairs were discordant for handedness (MZ-RL). Intraclass correlations for MZ twin pairs were weak or nonexistent for ear advantage, but relatively strong for overall correct scores and mean reaction times, measures unrelated to laterality scores. These results support the hypothesis that auditory lateralization, as measured with dichotic tests, is nongenetic in origin. A comparison of MZ twins and right-handed siblings (n = 20) showed that right-handed siblings exhibited strong REAs, whereas left-handed siblings (n = 20) and MZ twins showed weak or absent REAs, indicating that twins may be atypically lateralized with respect to auditory lateralization.

[1]  Michael C. Corballis,et al.  On the biological basis of human laterality: II. The mechanisms of inheritance , 1978, Behavioral and Brain Sciences.

[2]  S. Blumstein,et al.  The reliability of ear advantage in dichotic listening , 1975, Brain and Language.

[3]  S. Katz,et al.  Left-handedness in twins: Incidence and patterns of performance in an adolescent sample , 1976, Behavior genetics.

[4]  R. Collins.  On the inheritance of handedness. II. Selection for sinistrality in mice. , 1969, The Journal of heredity.

[5]  Robert J. Zatorre,et al.  Perceptual asymmetry on the dichotic fused words test and cerebral speech lateralization determined by the carotid sodium amytal test , 1989, Neuropsychologia.

[6]  P. Bakan.  Left handedness and birth order revisited , 1977, Neuropsychologia.

[7]  S. P. Springer,et al.  The ontogeny of hemispheric specialization: Evidence from dichotic listening in twins , 1978, Neuropsychologia.

[8]  L. Penrose,et al.  MONOZYGOTIC AND DIZYGOTIC TWIN DIAGNOSIS , 1955, Annals of human genetics.

[9]  D. A. Sprott,et al.  Statistical determination of degree of laterality , 1981, Neuropsychologia.

[10]  Fred H. Previc,et al.  A general theory concerning the prenatal origins of cerebral lateralization in humans. , 1991 .

[11]  J. Volkmann,et al.  Dichotic listening: What does it measure? , 1992, Neuropsychologia.

[12]  S. Holm.  A Simple Sequentially Rejective Multiple Test Procedure , 1979 .

[13]  E. Teng.  Dichotic ear difference is a poor index for the functional asymmetry between the cerebral hemispheres , 1981, Neuropsychologia.

[14]  C. Boklage.  DISCUSSION PAPER: EMBRYONIC DETERMINATION OF BRAIN PROGRAMMING ASYMMETRY‐ A CAUTION CONCERNING THE USE OF DATA ON TWINS IN GENETIC INFERENCES ABOUT MENTAL DEVELOPMENT * , 1977, Annals of the New York Academy of Sciences.

[15]  J. Richard Jennings,et al.  Editorial Policy on Analyses of Variance With Repeated Measures , 1987 .

[16]  T. Nagylaki,et al.  A model for the genetics of handedness. , 1972, Genetics.

[17]  L. J. Chapman,et al.  Artifactual and genuine relationships of lateral difference scores to overall accuracy in studies of laterality. , 1988, Psychological bulletin.

[18]  T. Nagylaki,et al.  “The Sound of One Paw Clapping” isn't sound , 1973, Behavior genetics.

[19]  G. P. King,et al.  Within-modal and cross-modal consistency in the direction and magnitude of perceptual asymmetry , 1990, Neuropsychologia.

[20]  T. F. Pugh,et al.  Influence of intrauterine relations on the intelligence of twins. , 1969, The New England journal of medicine.