Via: The Conversation
Today, we understand that handedness is not a binary characteristic (left or right), but rather, it exists along a gradient that ranges from strongly left-handed to strongly right-handed.
As children grow older, they tend to favour one hand over the other for certain tasks, particularly for writing or drawing. A child’s “handedness” is generally categorised as right, left or mixed, and tends to settle around the same time they acquire language – about four-years-old. It remains a persistent characteristic throughout our life.
The left and right hemispheres of the brain control motor action on the opposite sides of the body. Yet, the left and right halves of the brain are not equal in their control of different types of behaviours, which results in a bias of one hand over the other for certain tasks. The dominance of one hemisphere over the other for certain behaviours is called cerebral lateralisation.
As they start to develop their motor skills, children may use both the left and right hands equally for simple actions such as reaching for objects. This is because both hands can accomplish the task with ease.
Observing a child’s handedness for fine motor activities, such as writing, can give us an indication of how well the two hemispheres have developed their specialised processing capabilities.