Most babies use both hands to begin with, and rarely show any preference before about 7 to 9 months old. By about 18 months many children use one hand consistently, but 4 to 6 year old children may still be undecided as to their dominant hand.
Catching and throwing a ball is not always a good way to tell hand preference. Some ways to tell if your child is left-handed include:
About 10% of people are left-handed. Males are about twice as likely to be left-handed than are females.
Left-handedness is related to the brain, not the hand. It is not just a habit. There is no great disadvantage to being left handed. Many famous and successful people throughout history were left handed.
Left-handedness is more common in children with epilepsy, mental retardation, and autism. This may be due to early damage in the left side of the brain leading to the right side of the brain taking control of skilled hand movements. If you have concerns, have your child checked by your health care provider.
If you are right-handed, sit across from your child when teaching them to tie their shoe laces or get dressed. This gives them a mirror image to copy, and is easier than sitting beside them to demonstrate.
Lefties have to get special left-handed golf clubs, hockey sticks, and baseball mitts. They usually can't just borrow friends' equipment.
Left-handers should only use scissors designed for them. Scissors and saws for right-handed people can be dangerous for lefties. When your child reaches school age, make sure that he or she doesn't have to sit at desks for right-handers. When students begin to write, they should learn paper and pencil positions for the left-hander. For example, it helps for the left-hander to hold her or his pencil a little higher than the right-hander.