THE subject of hand dominance has been debated for several centuries, but only recently has the publication of sound advice trumped sensationalism.

The preference of one hand over the other can be demonstrated as early as in the uterus, when foetuses can be seen to pick the thumb of one hand to suck. After birth, early hand use develops between 7-9 months of age. However, at this time, and because actions are largely gross and don’t require much skill, the choice of hand can be as simple as that which is nearest to the object.

Between 18 to 24 months old children may start to favour a chosen hand, this decision usually being established at around 4 years of age, roughly in line with speech development. Children may still swap hands subconsciously until 8-9 years old, at which point it is fixed for the rest of their life, barring illness or injury.

Cross dominance refers to when one hand is used for a particular activity, such as writing, while the opposite hand is selected for other requirements, for example throwing a ball.

True ambidexterity, where both hands can be used with equal composure in all circumstances, is seen in an estimated 1-4% of the population. Left handers or “lefties” as they are sometimes affectionately referred to, make up 10%, with the remaining over 85% being right-handed.

From a parent’s perspective, perhaps the most important discussion is how to assist with the development of your child’s dexterity. Hand dominance is a subconscious decision, and it is recommended that you do not try to influence this.

Once a hand is selected current thinking favours you encourage your child to use this consistently, the theory being that one very well-developed hand is of more use than two that are averagely skilled. It will also allow your child to concentrate more on the task they are attempting.

Yet the non-dominant hand is equally important for stabilising objects as well as presenting them to the dominant hand.

Hand dominance is not automatically associated with brain development as previously thought. For example, the speech centre is located in the left half of the brain, irrespective of which hand is preferred.

There are milestones for manual dexterity, as per any aspect of development. If you are worried that your child is struggling, see your GP who can refer to a paediatric occupational therapist.