Left-handed people make up about 10% of the world's population. There’s a belief that left-handed people think differently due to brain function. The left brain controls the right side of the body and is often linked to logic, while the right brain, controlling the left side, is linked to creativity. This has led to the idea that left-handed people are more creative. While this isn't fully proven, it does make one wonder about the unique qualities of being left-handed.
The Science Behind Left-Handedness
Scientists have studied left-handedness for years, trying to understand why some people are left-handed. They have found that it’s partly genetic. If one parent is left-handed, there’s a higher chance their child will be left-handed. However, it's not just about genetics; the environment plays a role too.
Brain Lateralization
Brain lateralization refers to the specialization of functions in each hemisphere of the brain. For most people, the left hemisphere is dominant for language and logical tasks. And the right hemisphere handles spatial abilities (how well you understand and reason about the relationships between objects and spaces) and creative tasks.
This division is not absolute, but there are notable differences between left-handed and right-handed people.
Language and Handedness
Research shows that about 95% of right-handed people have left-hemisphere dominance for language. In contrast, left-handed people exhibit more variation.
Approximately 70% of left-handers also have left-hemisphere language dominance, 15% have right-hemisphere dominance, and the remaining 15% show bilateral (both hemispheres) language processing .
It suggests that lefties may have a more flexible brain organization. Studies using functional MRI (fMRI) have shown that left-handers often use both hemispheres for tasks typically managed by one hemisphere in right-handers. This bilateral usage might contribute to the perception that left-handed people are more creative or better at multitasking .
Health Links
Several interesting health correlations are associated with left-handedness. Some studies suggest that left-handed people may be more prone to certain conditions, but the evidence is complex and sometimes contradictory.
Developmental Disorders
- A study published in "Neuropsychologia" reported a higher prevalence of left-handedness in children with dyslexia compared to the general population .
- Similarly, left-handedness has been linked to ADHD, autism, and certain learning disabilities. These associations may be due to atypical brain development that also affects handedness.
Mental Health
Left-handedness has been associated with a higher incidence of mood disorders. A study published in "PLOS ONE" found that left-handed people have a slightly higher risk of developing schizophrenia and mood disorders like depression.
The reasons for these links are not fully understood, but it might be related to the atypical lateralization of brain function in left-handers.
Stroke Recovery
Interestingly, left-handed people may have an advantage in recovering from brain injuries, such as strokes. Because their brains are less lateralized, they might have a better ability to compensate for damage in one hemisphere by using the other.
A study in "Brain and Cognition" found that left-handers had a better recovery outcome after a stroke compared to right-handers, likely due to their more adaptable brain structure.
References
- Knecht, S., et al. (2000). Handedness and hemispheric language dominance in healthy humans. Brain, 123(12), 2512-2518.
- Toga, A. W., & Thompson, P. M. (2003). Mapping brain asymmetry. Nature Reviews Neuroscience, 4(1), 37-48.
- Geschwind, N., & Galaburda, A. M. (1985). Cerebral lateralization: Biological mechanisms, associations, and pathology: I. A hypothesis and a program for research. Archives of Neurology, 42(5), 428-459.
- Bourne, V. J. (2007). Handedness and schizophrenia: A meta-analysis. Neuroscience & Biobehavioral Reviews, 31(7), 1001-1013.
- Knecht, S., et al. (2002). Handedness and hemispheric language dominance in healthy humans. Brain, 125(4), 822-827.
Sports - Southpaw
Left-handed people often excel in sports and creative fields, and here's why:
- Element of Surprise: Most athletes train and compete against right-handed opponents. When they face a left-handed player, the angles and trajectories are different from what they usually encounter. This unfamiliarity can give left-handed athletes a competitive edge, as their moves and strategies are less predictable.
- Different Spin and Angles: In sports like tennis and baseball, left-handed players can deliver spins and angles that right-handed players find challenging to return. For example, a left-handed tennis player's serve can have a different spin and direction, making it harder for right-handed opponents to anticipate and react effectively.
- Positional Advantages: In combat sports such as boxing and fencing, left-handers often face right-handers who are not used to their stance. This "southpaw" position can be disorienting for right-handed fighters, who are less practiced in defending against and attacking left-handed opponents. The rarity of left-handed fighters means they bring an unconventional approach that can be difficult to counter.
- Strategic Play: In team sports like soccer, left-handed (or left-footed) players can be strategically valuable. Their ability to control and pass the ball with their left foot can open up different attacking angles and create opportunities that right-footed players might not see as easily. This can disrupt the defensive strategies of opponents who are more accustomed to right-footed play.
Historical Views on Left-Handedness
In many Western cultures, left-handedness was once considered a sign of bad luck or even evil. The word “sinister” comes from the Latin word for left. Left-handed children were often forced to use their right hand for writing and other tasks.
Today, left-handedness is generally accepted and even celebrated in many parts of the world. International Left-Handers Day, observed on August 13, recognizes the uniqueness of left-handed people. This day celebrates the creativity and adaptability of left-handed people and encourages right-handers to experience life from a left-handed perspective, even if just for a day.
Left-Handedness in Animals
Left-handedness appears in the animal kingdom too. Certain animals show preferences for one side over the other.
- Parrots: Often show a preference for using one claw over the other when handling objects, such as picking up food or toys.
- Chimpanzees: Display handedness similar to humans, with some chimps being left-handed while others are right-handed. This preference can influence their tool use and social interactions.
- Kangaroos: Studies have found that wild kangaroos show a strong preference for using their left hand when grooming, eating, or defending themselves.
- Cats and Dogs: Some cats and dogs show paw preference, with about 40% being left-pawed, 40% right-pawed, and 20% ambidextrous. This can be observed in which paw they use to reach for food or toys.
- Frogs: Certain species of frogs display handedness, such as the South American tree frog, which uses its left hand more frequently for tasks like climbing and capturing prey.
- Walruses: Tend to use their right flipper for foraging on the sea floor, suggesting a right-flipper preference similar to handedness in humans.
Leonardo Da Vinci
Famous lefties include Michelangelo, the genius behind the Sistine Chapel ceiling and the statue of David, as well as Albert Einstein, Bill Gates, Oprah, etc. They happened to be lefties and geniuses.
But Da Vinci is another brilliant lefty, was a painter, scientist, and inventor. You know from the Mona Lisa and The Last Supper. He wrote in mirror script, which some believe was because he was left-handed and wanted to avoid smudging his ink.
Modern Accommodations for Left-Handers
In today’s world, there is a growing awareness of the needs of left-handed people. Many products and tools are now designed to accommodate them.
Specialized Products
From left-handed scissors to computer mice, there are various products tailored for left-handed use. These tools make everyday tasks easier and more comfortable for left-handed people. Schools are also becoming more aware of the needs of left-handed students, providing desks and writing tools that cater to their unique requirements.
Online Networks
Left-handed people have formed online networks and support groups where they can share tips, experiences, and advice. These platforms provide a sense of belonging and practical help for navigating a right-handed world. By connecting with others who share their experiences, left-handed people can find support and encouragement.
