How and When Do Babies Choose a Favourite Hand?
It’s widely known that most adults are right-handed—around 90% of us, in fact! But what about babies? How do they decide which hand to use, and when do they show a clear preference?
Newborns start life with the ability to use both hands equally. However, over the first few years, you’ll notice them gradually starting to favour one hand. By the time they are around four years old (or even later for some), they’ll settle on their “dominant” hand, which they’ll likely use for the rest of their lives.
So, what causes this shift from equal-handedness to favouring one side? While researchers agree that genetics play a role (left-handed parents are more likely to have left-handed children), it’s not as simple as passing down a single gene. About half of the children born to left-handed parents still end up being right-handed. This means other factors, like environment, also have an impact. Babies often mimic what they see, so if they watch their parents using their left hand more, they might start using their left hand too!
A Peek Inside the Brain
Handedness isn’t just about which hand we prefer to write or throw a ball with—it’s deeply connected to the structure of the brain. The brain is divided into two hemispheres, and each hemisphere controls the opposite side of the body. That’s why your right hand is controlled by the left side of your brain and vice versa.
This brain structure starts to develop even before birth! In fact, studies show that babies as young as 13 weeks in the womb might suck their right thumb more often than their left, which could hint at future right-handedness.
The differences between the left and right brain also extend to how we process language. For example, right-handed people tend to have language centres in the left hemisphere, while left-handed people have them on the right side. The brain’s organisation reflects handedness, but exactly why this happens is still something researchers are trying to fully understand.
When Will Your Baby Show a Preference?
While it’s fun to guess which hand your little one will favour, it takes time for that preference to become clear. In the early months (around 4 to 6 months), babies start reaching for objects, and you might notice them holding a rattle longer in one hand. By 9 months, many babies will start consistently reaching for toys with their right hand. However, it’s still normal for them to switch between hands.
By 18 months, your child’s hand preference might start to become more obvious, but don’t be surprised if they switch sides for a while! It’s not until around 4 years old (sometimes as late as 7) that most children settle on one hand as their dominant side.
Interestingly, some children may never show a clear preference at all! A rare few are ambidextrous, meaning they can use both hands equally well. In other cases, children may show no clear hand dominance, using either hand for different tasks throughout their lives.
Fun Fact
Here’s a fun tidbit: if both parents are left-handed, there’s a 26% chance their child will be too. But if both parents are right-handed, the chances of having a left-handed child drop to just 10%. Even though genetics are part of the story, environment plays a big role too!
So, the next time you catch your little one reaching out with their left or right hand, remember they’re not just grabbing a toy—they’re revealing something fascinating about their developing brain! And who knows, maybe they’ll even end up using both hands equally!
