What is Handedness?
'''Handedness''' is the preference for using either the left or the right side of the body for certain things. People are described as [[left-handed]] or [[right-handed]] when they prefer to write with their left or their right hand. They may prefer the use of certain hands for certain tasks. [[File:تلميذة_تكتب_بيدها_اليسرى.jpg|thumb|right| A female student writes with her left]] Most people are [[right-handed]]. Many prefer to use their right [[eye]], right [[foot]] and right [[ear]] if forced to make a choice between the two). The reasons for this are not fully understood. [[Ambidexterity]] is when a person has approximately equal skill with both [[hand]]s and/or both sides of the body. True ambidexterity is very rare. In some sports work is done to even up the influence of the non-dominant side. [[Soccer]] is a good example. == Handedness and brain function == Handedness is caused by the [[Lateralization of brain function|lateralisation of brain function]].<ref>Annett, Marian 2013. ''Handedness and brain asymmetry: the right shift theory''. London: Taylor Francis. {{ISBN|9780415648264}}</ref> Lateralisation is not only found in [[human]]s: it is found in many kinds of [[animal]]s. Handedness seems to follow from the brain hemisphere division of labor. In most people the left side of the brain controls [[speech|speaking]], and the left [[cerebral hemisphere]] of the [[brain]] controls the right side of the body.<ref>As the motor nerve fibres move down through the lower part of the brain, they cross over to the opposite side of the body. So, the movements on each side are controlled by the opposite side of the brain. Rosenbaum, David A. 1991. ''Human motor control''. San Diego, CA: Academic Press, p. 411. {{ISBN|0-12-597300-4}}</ref> In 90-92% of all humans, the left hemisphere is the [[language]] hemisphere. Therefore right-handedness predominates. This theory predicts that left-handed people have a reversed brain division of labor.<ref name=book>{{cite book |last=Banich, Marie 1997. |title=Neuropsychology