Laterality & Left-Handedness: How the Brain Defines Our Dominant Side

Laterality refers to the preference for one side of the body – like hand, foot, eye or ear. But what does that mean for left-handers?

Laterality describes the functional asymmetry of the human body – the preference for using one side over the other for specific tasks. The most well-known example is handedness, but laterality also applies to the foot, eye, and ear. This preference is closely connected to how our brain hemispheres specialize.

How does laterality develop?

The brain consists of two hemispheres that manage different functions. The left hemisphere controls the right side of the body and is often responsible for language and logic. The right hemisphere manages the left side and is associated with creativity and spatial skills. This division leads to a preference for one side – known as laterality.

Left-handedness as a natural variation

Left-handedness is a natural form of laterality and a normal variant in human development. Around 10–15% of people are left-handed. Interestingly, while left-handers often show right-brain dominance, about 70% still have their language center in the left hemisphere – showing that the brain–handedness link is complex.

Mixed forms of laterality

Laterality isn't always clear-cut. Common mixed forms include:

Crossed laterality: The dominant hand and dominant eye are on opposite sides of the body.
Ambiguous laterality: No strong dominance – both sides are used equally for tasks.

Mixed laterality isn't necessarily a problem, but can impact learning, especially when it comes to writing or reading.

Scientific insights

Research suggests laterality begins to develop prenatally and is shaped by both genetic and environmental factors. The process of establishing handedness is complex, but can be supported through observation and appropriate guidance.

Conclusion

Knowing one’s dominant side – especially hand dominance – is important for personal development and learning. If you're unsure about a child's laterality, a professional assessment can provide clarity and help avoid issues like forced retraining.

Have questions about laterality or left-handedness? Just ask the Left-Handed Store – we’re happy to help!

Frequently Asked Questions about Laterality & Left-Handedness

What does laterality mean?

Laterality refers to the preferred use of one side of the body – such as hand, foot, eye, or ear. It results from the way our brain hemispheres divide tasks.

How can I tell if my child is left-handed?

Through careful observation and, if needed, a professional laterality assessment. These tests help determine hand dominance – especially important before school starts.

What is crossed laterality?

Crossed laterality means the dominant hand and dominant eye are on opposite sides – for example, a right-handed child with a dominant left eye.

Can you “retrain” laterality?

This is not recommended. Retraining handedness can lead to long-term problems. It's better to support a child's natural dominant side.

Why is laterality important for learning?

Stable laterality supports brain organization for tasks like reading and writing. Unclear or mixed laterality may lead to learning difficulties if left unaddressed.