Left-Handedness: A Fact, Not a Mental Disorder

Does left-handedness describe a mental disorder? Absolutely not. It is a natural variation seen in about 10% of the population and has no obvious scientifically proven advantages.

Understanding the Neuroscience of Left-Handedness

The human brain is complex, with the sensation and motor connections typically occurring on the opposite side of the body from the brain areas that control them. This means that the control center for the left hand is located on the right side of the brain, and vice versa.

If the left side of your brain experiences a severe injury, you might experience paralysis on your right side. This connection is facilitated by the corpus callosum, a structure located in the center of the brain that allows the two hemispheres to communicate with each other. This cooperation is how your left hemisphere can efficiently prepare your right foot to step after your left foot has taken a step.

While this is a simplified explanation, it illustrates the intricate nature of brain functions and reveals why left-handed people are often joked about in a non-serious manner by neuropsychologists.

Genetics and Brain Plasticity

Being left-handed is often a genetic trait. However, it is not always that straightforward. The brain, especially in its early years, is highly plastic and can adapt to changes. If a person born as a right-hander suffers a severe head injury, high fever, or some kind of illness, their brain can rewire itself to function around the damage. This reconfiguration can result in left-handedness.

While this re-wiring is more common in younger individuals, older people may still experience such changes, but the effects are generally less pronounced. The plasticity of the brain decreases with age, and the trauma itself might have other consequences, such as minor learning difficulties.

Determining Your Hand Preference

To determine whether you were born or made left-handed, you can look at your family history. If you have a close relative who is left-handed, it is likely a genetic trait. Conversely, if you are the only left-hander within several generations including aunts, uncles, and cousins, you might be a "surprise" left-hander.

But, rest assured, being left-handed does not imply any mental disorder. It simply reflects the unique way your brain is structured and developed.

So, embrace your left-handedness, whether it is a genetic trait or a result of brain plasticity. You're not wrong, you're just in your right mind!