A new study suggests lefties are rare because of the balance between cooperation and competition in human evolution. Researchers at Northwestern University now report that a high degree of cooperation, not something odd or sinister, plays a key role in the rarity of left-handedness.

The definition of ambidextrous is the ability to use both the left and right hand equally well. An example of ambidextrous is a person who can write with his left hand and his right hand.

1a : using both hands with equal ease or dexterity an ambidextrous pitcher Guatelli says the master was ambidextrous, that he sketched with his right hand while he wrote with his left—simultaneously.

A study of 11-year-olds in England showed that those who are naturally ambidextrous are slightly more prone to academic difficulties than either left- or right-handers. Research in Sweden found ambidextrous children to be at a greater risk for developmental conditions such as attention-deficit hyperactivity disorder.

• It feels the same with both hands.
• It feels like you applied a little more pressure with your dominant fist.
• It feels like you applied a lot more pressure with your dominant fist.

The study found that left-handers and right-handers had similar IQ scores, but people who identify as ambidextrous had slightly lower scores, especially in arithmetic, memory and reasoning.

No differences in mean IQ scores were found between right-handers and non-right-handers as well as between right-handers and mixed-handers. No sex differences were found. Overall, the intelligence differences between handedness groups in the general population are negligible.

According to a recent global sex survey, it seems that the lefties among us are having a much better time between the sheets than their right-handed counterparts, and by a long way too.

Others studies have found that lefties are overrepresented among high achievers or people with high IQs, according to an article in the New Yorker. That same article also noted that there are also a high number of left-handers in occupations like architects and musicians.

Lefties make up only about 10 percent of the population, but studies find that individuals who are left-handed score higher when it comes to creativity, imagination, daydreaming and intuition. They’re also better at rhythm and visualization.

A 1967 study by Douglas, found no evidence to correlate mathematical ability with left-handedness or ambidexterity. The study compared the people who came in the top 15% of a mathematics examination with those of moderate mathematical ability, and found that the two groups’ handedness preferences were similar.

They found that for different types of word-memory tasks, participants with left-handed relatives had a better memory when it came to recalling events, and an inferior implicit memory. Meanwhile in a second experiment, the researchers studied episodic and semantic (factual) memory in 84 right-handed undergraduates.

Left-handers, who make up 15 percent of the population, don’t have a monopoly on memory, though. The experiments showed that semantic memory was stronger in those individuals with all right-handed relatives, or when words were presented to just one side of the visual field.

Special or not, lefties are born, not made: Genetics are at least partially responsible for handedness. Up until last year, it was assumed that hand preference comes from asymmetrical genes in the brain—two hands, two brain hemispheres, one is dominant.

Superior Lefties? Your brain’s right side controls muscles on the left side of your body and largely drives musical and spatial abilities. That may be why left-handers often hold more than their share of slots in creative professions.

Southpaws

Cross-dominance is also known as mixed-handedness and occurs when a person favours one hand for certain tasks and the opposite hand for other things. For example, a mixed-handed person might write with their right hand and do everything else with the left one. A right-handed person may be stronger on the left side.

Overall, left-handers are not more creative and are not more right-brained, artistic and less logical than right-handers. Left-handers do not live shorter lives and the average left-hander is no more prone to accidents or disease than the average right-hander.

Handedness. There is a persistent popular belief that Einstein was left-handed, but there is no evidence that he was, and the belief has been called a myth. Einstein wrote with his right hand, and authoritative sources state flatly that he was right-handed.

Like most aspects of human behavior, handedness is a complex trait that appears to be influenced by multiple factors, including genetics, environment, and chance. More specifically, handedness appears to be related to differences between the right and left halves (hemispheres) of the brain.

In two studies, Diana Deutsch found that left-handers, particularly those with mixed hand preference, performed significantly better than right-handers in musical memory tasks. There are also handedness differences in perception of musical patterns.

Lefties get angrier A study in The Journal of Nervous and Mental Disease suggested that those who are left-handed are more prone to negative emotions. It also found that when processing emotions, lefties have a greater imbalance in activity between the left and right brains.

One potentially important determinant of a child’s cognitive development is the preference for using the left or right hand. Left- or mixed-handedness has been associated with atypical cognitive abilities, which can have both disadvantageous and advantageous outcomes (Heilman 2005).

right hand

Not only did Leonardo write with a special kind of shorthand that he invented himself, he also mirrored his writing, starting at the right side of the page and moving to the left. People who were contemporaries of Leonardo left records that they saw him write and paint left handed.

Vincenzo Peruggia

Leonardo da Vinci is one of history’s most famous lefties. He was known by his contemporaries as “mancino”—Italian slang for a left-handed person—and experts today use signs of left-handedness to authenticate the artist’s work, particularly his drawings.

The takeaway. While there are curious differences between lefties and righties, a higher intelligence level probably isn’t one of them. Many studies show mixed results when examining this complicated link, leading researchers to conclude that left-handed people are no smarter than their right-handed counterparts.

67 years (1452–1519)

Van Gogh was right-handed. We are almost certain of this, because in two self-portraits, he’s pictured with the pallet in his right hand.