Handedness is a human attribute defined by unequal distribution of fine motor skills between the left and right hands. An individual who is more able with the right hand is called right-handed and one who is more skilled with the left is said to be left-handed. The majority of infants have developed hand preference at 6 months of age. A minority of adult people are equally skilled with both hands, and are termed ambidextrous. It is one example of body laterality.
The reasons for handedness, and why right-handedness is dominant are not known for certain, but a number of theories have been proposed.