Asymmetry relations between laterality IQ memory and management of dominant hemispheres in twins

Lateral preferences in humans may be a key to many important topics in biology and physiology. However, less information is known about genetic and environmental factors for lateral preference. Comparisons of MZ (monozygotic) and DZ (dizygotic) twins can indicate which characters are hereditary or environmental. The aim of this study is to investigate morphological, functional and cognitive lateralities in twins in terms of hereditary and environmental factors. For this aim, the handedness, body laterality (motor), IQ (mental), hemispheric dominance (cognitive) and morphological properties such as head diameter, hand and foot dimensions (anatomical) were measured to determine asymmetry traits on 100 MZ, 92 DZ twin pairs. As compared with DZ twins, the correlations among the studied traits (IQ, visual memory, anatomical features, brain lateralization and handedness) were found higher in MZ twins.