Neonatal laterality, birth stress, familial sinistrality, and left‐brain inhibition

Abstract

In order to determine the influence of birth stress, familial sinistrality, and their interaction effects on neonatal laterality in head‐turning and in manual activity, 46 2‐day‐olds participated in a study involving baseline conditions and responses to auditory stimulation. Low intensity speech and music stimuli (2 sec) were presented from behind at the midline while the neonates were alert and holding a bar. Analysis of variance (ANOVA) revealed relatively more right turning to speech, in particular. Multiple regression analyses especially highlighted the variance in neonatal laterality explained by familial sinistrality. Birth stress and its interaction with familial sinistrality were also important in the baseline condition. Conclusions emphasize genetic influences on congenital left‐brain specialization for receptive language and concomitant inhibitory skills.