Superstition regarding left hand dominance was so strong that in medieval times the word "sinister" was used to describe the left hand. Even up to the 1970's, parents received tips on how to encourage right-hand dominance over left.
This prejudice is slowly losing its hold. Rather than discouraged, left-handed students are accommodated with schools now providing left-handed scissors and not assuming right hand dominance. But what if a child has difficulty establishing hand dominance?
Hand dominance takes many forms and can be subjective. This is how it develops and when it can become an issue.
Dominant Hand Development
Hand dominance is based on unique brain structure and has a strong genetic component. Right hand dominance is most common with left hand dominance estimated at 10%.
The dominant hand handles tools and directs fine and grapho motor skills. The less dominant hand stabilizes the project. For example, a child will hold a paper with one hand and write with the other.
This dynamic starts developing at 10 to 18 months: Children will start to stabilize with one hand and manipulate with another--for example, hold a drum with the right hand and use the drumstick with the left. From 18 months to three years old, both hands manipulate but perform different actions as hand dominance establishes. This process can complete as early as age four but age seven is typical.
Variations in Dominance
A very small population is ambidextrous, which is the ability to use both hands with equal skill. Estimated to be about 1% of the population, ambidextrous individuals can use either hand for fine motor tasks including using scissors or writing. It arises more out of environmental factors such as seriously injuring the predisposed dominant hand or having left hand dominance discouraged.
Mixed hand preference arises in people who interchange their dominance and is often confused with being ambidextrous. For example, a left hand writer may swing a baseball bat right handed or a student may cut paper with one hand and write with the other. This dominance is normally task-specific with the switched dominance often associated with more full-body activities, like swinging a golf club.
Ambidextrous, Mixed-Hand Preference or Dyspraxia?
If a child has a lack of hand dominance, is it an issue of being ambidextrous, mixed-hand or a learning disability?
As noted above, being ambidextrous is very uncommon and unless an environmental factor interfered, it is an unlikely outcome. However, it is not impossible and a child may show coordination with both hands despite experiencing nothing to require that development. The precaution here is to help her complete tasks without confusion on which hand to use. It will normally evolve to mixed-hand usage.
With mixed hand preference, as long as the quality of schoolwork is not compromised by finishing different tasks with different hands there is no reason to change it. Simply encourage the student to keep the preferences consistent and not switch a task to the other hand.
However, difficulty establishing dominance and developing these skills can suggest a learning disability. Dysgraphia is a learning disability concerning motor skills development. Children with dysgraphia will have issues gripping pencils and other tools, conceptualizing left and right, and even walking, jumping, skipping, or catching balls. Not only is establishing hand dominance difficult but so are a variety of other physical tasks.
Like learning disabilities that affect reading and math, dysgraphia can also be assessed and treated with educational therapy. If schoolwork suffers due to difficulty with writing or other motor skill tasks, contact us to start the process in overcoming this difficulty.