Just like almost everyone knows a friend named “John,” nearly everyone has encountered a left-handed person at some point. Left-handed people, or “lefties,” prefer using their left hand for tasks like writing and eating, which differs from the majority who are right-handed.
Are Lefties Really Smarter?
Left-handedness is not a rare phenomenon. Research involving 2.4 million people found that about 10.6% of the population is left-handed. This means, on average, one in ten people is a lefty.
Because left-handed people are a minority, there is a lot of curiosity about how they differ from right-handed people. This curiosity has led to the common belief that left-handed people are more intelligent. Some “pseudo-science” articles even claim that geniuses like Einstein and Newton were left-handed, though old photos suggest this is likely a myth.
In reality, being left-handed does not make someone smarter. A 2006 study with 255,100 participants found no significant IQ differences between left-handed and right-handed people. However, left-handed individuals may have an advantage in certain sports like tennis and ping-pong, possibly due to their unique movements that can confuse opponents.
So, if intelligence isn’t linked to handedness, why are there fewer left-handed people?
Why Are There Left-Handed People?
To understand why there are fewer left-handed people, we need to look at human evolution, particularly the development of language. Early humans likely used both hands equally, but the brain’s language centers are predominantly in the left hemisphere, which controls the right side of the body. As language became more important, the left hemisphere became more dominant, making right-hand use more common. This is one theory, but it is not the only one.
Another prevailing theory is that left-handedness is related to genetic mutations. Hand preference develops early in life; about 39% of infants show hand preference between 6 to 14 months old, and by 18 to 24 months, 97% have established a dominant hand.
Studies on fetuses have shown that hand preference can be determined in the womb, accurately predicting the child’s hand preference after birth.
Scientists at Oxford University studied 3,300 volunteers and identified a gene called PCSK6 as being associated with handedness. This gene plays a crucial role in the development of the body’s left-right asymmetry. In experiments with mice, deleting this gene caused their organs to develop on the opposite side.
Interestingly, the PCSK6 gene is also linked to language function. Mutations in this gene can lead to speech disorders. While genetics play a significant role, they do not explain all cases of left-handedness, indicating that future discoveries may provide a fuller picture.
In Summary:
- Left-handed people are a minority, making up about 10% of the population.
- There is no significant IQ difference between left-handed and right-handed people.
- Left-handedness may result from genetic mutations.
So, while lefties may seem unique, they are not necessarily smarter than their right-handed counterparts. They do, however, add an interesting variety to the human experience.
