A person's preference for one hand when performing manual tasks.

The term handedness describes a characteristic form of specialization whereby a person by preference uses one hand for clearly identified activities, such as writing. For example, a person who uses his or her right hand for activities requiring skill and coordination (e.g., writing, drawing, cutting) is defined as right-handed. Roughly 90% of humans are right-handed. Because left-handed children who are forced to write with their right hand sometimes develop the ability to write with both hands, the term ambidexterity is often used in everyday parlance to denote balanced handedness.

An often misunderstood phenomenon, handedness is a result of the human brain's unique development. While the human mind is intuitively understood as a single entity, research in brain physiology and anatomy has demonstrated that various areas of the brain control different mental aptitudes, and that the physiological structure of...