Humans display a large number of lateralized behaviors that are immediately visible such as handedness or footedness. These asymmetries are not limited to behavioral actions, but are also manifest in hemispheric lateralization of cognitive functions such as language or emotional processing. It is however unclear to what extent different asymmetries of brain and body correlate with one another. In this study, scientists from Bochum and Dresden investigated a large scale sample of over 1500 individuals with respect to their handedness, footedness and language lateralization using a dichotic listening task. We found almost no evidence that motor asymmetries and language lateralization were associated with one another using continuous lateralization quotients. On the contrary, we even found evidence that there is no link between these variables. These results indicate that previous studies suggesting an association between motor and cognitive hemispheric asymmetries might have overestimated their common biological and genetic basis.

Packheiser, J., Schmitz, J., Arning, L., Beste, C., Güntürkün, O. and Ocklenburg, S.. A large-scale estimate on the relationship between language and motor lateralization. 2020, 10:13027.