Left Hand

A variety of studies suggest that 10% of the world population are left-handed. Statistics show left-handed people are more likely to be schizophrenic, alcoholic, delinquent, dyslexic, and have Crohn's disease and ulcerative colitis, as well as mental disabilities. They're also more likely to die young and get into accidents. So if evolutionary theory dictates survival of the fittest, why do lefties still exist?

Negative asociations

Historically, the left side, and subsequently left-handedness, was considered negative in many cultures. The Latin word sinistra originally meant "left" but took on meanings of "evil" or "unlucky" by the Classical Latin era, and this double meaning survives in European derivatives of Latin, and in the English word "sinister". Alternatively, sinister comes from the Latin word sinus meaning "pocket": a traditional Roman toga had only one pocket, located on the left side. The right hand has historically been associated with skill: the Latin word for right-handed is dexter, as in "dexterity", meaning manual skill. Even the word "ambidexterity" reflects the bias. Its intended meaning is "skillful on both sides". However, since it keeps the Latin root dexter, which means "right", it ends up conveying the idea of being "right-handed at both sides". In Chinese culture, the adjective "left" (Chinese: 左; pinyin: zuǒ) sometimes means "improper" or "out of accord". For instance, the phrase "left path" (Chinese: 左道; pinyin: zuǒdào) stands for unorthodox or immoral means.n Hebrew, as well as in other ancient Semitic and Mesopotamian languages, the term "left" was a symbol of power or custody. The left hand symbolized the power to shame society, and was used as a metaphor for misfortune, natural evil, or punishment from the gods. This metaphor survived ancient culture and was integrated into mainstream Christianity by early Catholic theologians, such as Ambrose of Milan, to modern Protestant theologians, such as Karl Bart To attribute natural evil to God in explaining God's omnipotence over the universe.

Positive connotations

Among Incas left-handers were called (and now are called among the indigenous peoples of the Andes) lloq'e (Quechua:lluq'i) which has positive value. Indigenous peoples of the Andes consider that left-handers possess special spiritual abilities, including magic and healing.

The Third Sapa Inca — Lloque Yupanqui — was left-handed. His name when translated from Quechua means "the glorified lefthander". (However, this cannot be considered a positive connotation, since Lloque was known as "The Unforgettable Left-Handed One", owing to his reportedly horrifying ugliness.)

In China and Japan, the formula "man left, woman right" ( nán zuǒ, nǚ yòu) expresses the traditional concept that the left is the yang , yáng) direction and side of the body. The character for "left", 左, also depicts a left hand attending to its work. In contrast, the character for "right", (yòu), depicts a right hand in relation to the mouth, suggesting the act of eating.

In Tantric Buddhism, the left hand represents wisdom.

In early Roman times, the left side retained a positive connotation, as the Augures proceeded from the eastern side.]The negative meaning was subsequently borrowed into Latin from Greek, and ever since in all Roman languages.

In Russian, "levsha" (lefty, lefthander) became a common noun for skilled craftsman, after the title character from "The Tale of Cross-eyed Lefty from Tula and the Steel Flea" written in 1881 by Nikolai Leskov.

Intelligence

In his book Right-Hand, Left-Hand, Chris McManus of University College London argues that the proportion of left-handers is increasing and left-handed people as a group have historically produced an above-average quota of high achievers. He says that left-handers' brains are structured differently in a way that increases their range of abilities, and the genes that determine left-handedness also govern development of the language centres of the brain.

In a 2006 U.S. study, researchers from Lafayette College and Johns Hopkins University concluded that there was no scientifically significant correlation between handedness and earnings for the general population, but among college-educated people, left-handers earned 10 to 15 % more than their right-handed counterparts

According to new theories, what left-handed people (and other animals) may lack in fitness, they make up by being different."The fact that left-handers are less common means they have a surprise effect," said Faurie.

To prove their theory, Faurie and Raymond surveyed nine primitive societies in five separate continents. Through a mix of direct observation and existing data, they estimated the number of left-handed people within each population. They also looked at murder rates, thinking that those communities with higher murder rates might favor populations with more left-handed people. The more violence, the more chances lefties would have at issuing their unexpected left hook, or other such weapon, and come out on top.Other research is suggesting that humans aren't the only species who have minorities of certain side-favoring individuals. The equivalent of lefties has been observed in chimpanzees, toads, even among schools of fish.Favoring one side -- a result of something called lateralization of the brain -- was once thought to be a uniquely human trait linked to language. The ability to speak comes mostly from left regions of the brain, so the assumption was this would correspond with increased motor control on the opposite, or right side. In motor control, activity on one side corresponds to the opposite side of the brain. So this could explain why about 70 percent to 90 percent of people are right-handed.But lately, researchers who study animals have been poking holes in that idea.Evidence has shown a link between trauma during gestation or during birth, as well as in the age of the mother and so-called pathological left-handedness. Numbers show that mothers who are over 40 at the time of their child's birth are 128 percent more likely to have a left-handed baby than a woman in her 20s.

"Handedness is controlled by a whole lot of pathways in the brain and if any one of these pathways is mucked up during gestation, then handedness becomes a cosmic dice game," said Stanley Coren, a psychologist at the University of British Columbia and author of "The Left-Handed Syndrome." "We believe this accounts for about half of all left-handers."It could be that this early trauma is also the trigger behind health problems linked to left-handedness. Coren points to two famous left-handers, Presidents Bill Clinton and George H.W. Bush, as evidence. Both had histories of birth stress and have health issues from Clinton's severe allergies to Bush's Graves' disease.Then again, as many lefties might point out, being left-handed can also offer intellectual prowess. Tests conducted by Alan Searleman from St Lawrence University in New York found there were more left-handed people with IQs over 140 than right-handed people. Famous left-handed thinkers in history from Albert Einstein to Isaac Newton to Benjamin Franklin seem to underline the point."The anomaly is left-handed people make up the extremely gifted and the extremely compromised," said Hopkins. "The rest of us make up the middle ground."