As kids mature, they start favouring one hand over the other for major tasks like writing and drawing. But how do kids end up being left or right handed? Is it something that’s coded in their genetics? Or is it really just a matter of personal preference? Let’s take a closer look.
Kids are either categorised as left, right or mixed ‘handed’. This settles around the same time they acquire language skills, which is when they’re about the time they’re four years old. Once they select their favourite, it’s something that tends to stick with them for life.
Left or right handed – the stats around the world
The majority of the world population (roughly 90%) is right-handed. Before they can grasp complex skills like language, kids first have to develop basic sensory and motor abilities. Some experts believe that fine motor capabilities set the stage for acquiring systems necessary for the development of language. After the language is in place, kids decide whether they are left or right handed.
Left or right-handed, or perhaps both?
Prior to the 20-th century, scientists believed left-handedness to be a developmental abnormality. They associated it with dysfunctions like language deficits and mental health disorders. In this era, many left-handed kids were forced to write with their right hands in an attempt to try and “save” them.
Luckily we now understand that handedness isn’t a binary characteristic. We know that it rather exists along a gradient that ranges from strongly left-handed to strongly right-handed. Some kids are right handed when they write but left-handed when they play musical instruments, and vice versa.
Where it all starts
Kids use both their left and right hands when they first start developing their motor skills. Both hands can accomplish simple tasks, so there’s no reason to prefer one over the other. But, for most people, more complex tasks require specialised processing properties of the left hemisphere of the brain. That’s why most kids prefer their right hands for tasks such as writing. There are just 3-4% of the world population that is ambidextrous, meaning they are left-and-right-handed. Kids that have autistic spectrum disorders are most likely to be ambidextrous.