Keywords: Lateralization, head-orientation, handedness, early infancy, dynamic systems
The present review analyses the most important scientific works on the postural and motor functional asymmetries that characterize infants' head orientation and handedness. The main factors that cause and influence these body asymmetries in the early development were discussed. Furthermore, a summary of the evolutionary path followed by these different body lateralizations was suggested. Finally, it was possible to infer that the emergence of head orientation and handedness is the result of a complex interaction between genetic and environmental factors. To give a proper theoretical framework to this analysis, the dynamic system theory was proposed as an alternative explanation of the origins of lateralization.