Handedness is a better (faster or more precise) performance or individual preference for use of a hand, known as the dominant hand. Handedness is not a discrete variable (right or left), but a continuous one that can be expressed at levels between the strong left and strong right.
There are four types of handedness: left-handedness, right-handedness, mixed-handedness, and ambidexterity. Left-handedness is somewhat more common among men than among women.
- Right-handedness is most common. Right-handed people are more skillful with their right hands when performing tasks. Studies suggest that 87–92% of the world population are right-handed.
- Left-handedness is less common than right-handedness. Left-handed people are more skillful with their left hands when performing tasks. Studies suggest that approximately 10% of the world population are left-handed.
- Cross-dominance or Mixed-handedness is the change of hand preference between tasks. This is common in the population with about a 30% prevalence.
- Ambidexterity is exceptionally rare, although it can be learned. A truly ambidextrous person is able to do any task equally well with either hand. Those who learn it still tend to favor their originally dominant hand.
- Ambilevous or ambisinister people demonstrate awkwardness with both hands. Ambisinistrous motor skills or a low level of dexterity may be the result of a debilitating physical condition, such as “dysgraphia”