Handedness (dominant arm) is a term used to describe the ability of using right or left arm not only for writing but also for performing delicate and precise tasks. In fact, dominant arm appears even in prehistoric time. From the aspect of evolution, dominant arm is seen as an ability which correlates with speech development, and as such is related to cerebral lateralization. However, various cognitive disorders are connected to the dominant arm. The influence of inheritance and environment are equally important for the dominant arm, however their influence prevents us to determine how a certain arm becomes dominant.
