Left-handedness is the preference for the left hand over the right for everyday activities such as writing. "Handwriting" redirects here For scripts for writing down notes by hand see " Cursive " Most left-handed people favor their right hand for some activities, and many exhibit some degree of ambidexterity. Ambidexterity is the state of being equally adept in the use of both right and left Appendages (such as the Hands) ^[1] Left-handedness is relatively uncommon; over 90% of the adult population is right-handed. Someone who is right-handed will prefer to use this hand for everyday activities such as writing, maintaining personal hygiene, Cooking and so forth Being left-handed can be advantageous in some sports and games, although sometimes special equipment is required. Some everyday items such as scissors and other tools also have left-handed variants. Scissors are hand operated cutting instruments consisting of a pair of Metal Blades connected in such a way that the blades meet and cut materials placed

Demographics

Left Handers' Day, August 13, 2002

In 1998, a study suggested that approximately 7 to 10 percent of the adult population was left-handed. Events 3114 BC - According to the Lounsbury correlation the start of the Maya calendar. See also 2002 (disambiguation Year 2002 ( MMII) was a Common year starting on Tuesday of the Gregorian calendar. Studies indicate that left-handedness is more common in males than females. ^[2] Left-handedness, in comparison to the general population, also appears to occur more frequently in both identical and fraternal twins,^[3][4] and several groups of individuals with neurological disorders (such as people with epilepsy,^[5] Down's Syndrome,^[6] autism,^[7] mental retardation^[8] and dyslexia). Twins are Offspring resulting from the same Pregnancy, either of the same or opposite Sex. Epilepsy is a common chronic Neurological disorder that is characterized by recurrent unprovoked seizures. Down syndrome, Down's syndrome, or trisomy 21 is a Chromosomal disorder caused by the presence of all or part of an extra 21st chromosome. Language development. The terminology Mental retardation is a generalized triarchic disorder characterized by subaverage cognitive functioning and deficits in two or more adaptive behaviors with onset before the age Dyslexia is considered to be a Learning disability. It manifests primarily as a difficulty with written language particularly with Reading and Spelling Statistically, the identical twin of a left-handed person has a 76 percent chance of being left-handed, identifying the cause(s) as partly genetic and partly environmental. Genetics (from Ancient Greek grc-Latn genetikos, “genitive” and that from grc-Latn genesis, “origin” a discipline of Biology, is The social environment (context, also known as the Milieu, is the identical or similar Social positions and Social roles as a whole that influence the individuals ^[9]

Causes of left-handedness

Main article: handedness

• Hand orientation is developed in unborn children, most commonly determined by observing which hand is predominantly licked or held close to the mouth. Handedness is an attribute of human beings defined by their unequal distribution of Fine motor skill between the left and right Hands. Current genetic research suggests there is a genetic factor involved.
• In 2007, researchers discovered LRRTM1, the first gene linked to increased odds of being left-handed. LRRTM1, or Leucine-rich repeat transmembrane neuronal protein 1, is the first Gene linked to increased odds of being Left-handed. The researchers also claim that possessing this gene slightly raises the risk of psychotic mental illnesses such as schizophrenia. Schizophrenia ( from the Greek roots schizein (σχίζειν "to split" and phrēn ^[10]
• Long-term impairment of the right hand: People with long-term impairment of the right hand are more likely to become left-handed, even after their right hand heals. Such long term impairment is defined as 8 months or more.
• Testosterone: Exposure to higher rates of testosterone before birth can lead to a left-handed child. Testosterone is a Steroid hormone from the Androgen group In mammals testosterone is primarily secreted in the testes of males and the Ovaries ^[11] This is the Geschwind theory, named after the neurologist who proposed it, Norman Geschwind. Norman Geschwind (1926-1984 can be considered the father of modern Behavioral neurology in America It suggests that variations in levels of testosterone during pregnancy shape the development of the fetal brain. Testosterone suppresses the growth of the left cerebral hemisphere and so more neurons migrate to the right hemisphere. A cerebral hemisphere ( hemispherium cerebrale) is defined as one of the two regions of the Brain that are delineated by the body's median plane. The highly developed right hemisphere is now better suited to function as the center of language and handedness. The fetus is more likely to become left-handed, since the right hemisphere controls the left half of the body. The theory goes on to tie the exposure to higher levels of testosterone and the resultant right-hemisphere dominance to auto-immune disorders, learning disorders, dyslexia, and stuttering, as well as increased spatial ability. Autoimmunity is the failure of an organism to recognize its own constituent parts as self, which results in an immune response against its own cells and tissues In the United States and Canada, the term learning disability (LD refers to a group of disorders that affect a broad range of academic and functional skills including Dyslexia is considered to be a Learning disability. It manifests primarily as a difficulty with written language particularly with Reading and Spelling Spatial visualization ability or Visual-spatial ability is the ability to mentally manipulate 2-dimensional and 3-dimensional figures
• Ultrasound theory: Ultrasound scans may affect the brain of unborn children, causing higher rates of left-handedness in children born to mothers who have ultrasound scans compared to those who do not. Not to be confused with Supersonic. Ultrasound is cyclic Sound pressure with a Frequency greater than the upper This is probably based on a few studies^[12][13] where this relation is studied. In one of these the authors claim that ". . . we found a possible association between routine ultrasonography in utero and subsequent non-right handedness among children in primary school. " However later in the same article the authors state that "Thus the association . . . may be due to chance" and "The result was not significant, suggesting that the study had insufficient statistical power to resolve the relationship between ultrasonography and subsequent left handedness in the child"

Social stigma and repression of left-handedness

Negative associations of left-handedness in language

There are many colloquial terms used to refer to a left-handed person. Some are just slang or jargon words, while others may be offensive or demeaning, either in context or in origin. In more technical contexts, 'sinistral' may be used in place of 'left-handed' and 'sinistrality' in place of 'left-handedness'. Both of these technical terms derive from sinister, a Latin word meaning 'left'. ^[14]

Some left-handed people consider themselves oppressed, even to the point of prejudice. Etymology often lends weight to the argument:

In Hebrew, as well as in other ancient Semitic and Mesopotamian languages, the term "hand" was a symbol of power or custody. Etymology is the study of the History of Words &mdash when they entered a language from what source and how their form and meaning have changed over time The Semitic languages are a Language family whose living representatives are spoken by more than 467 million people across much of the Middle East, Mesopotamia (from the Greek meaning "land between the rivers" is an area geographically located between the Tigris and Euphrates rivers largely corresponding ^[15] The left hand symbolized the power to shame society, and was used as a metaphor for misfortune, natural evil, or punishment from the gods. Natural evil (also known as surd evil) is the result of any event perceived to be morally negative and that is not caused by the action or inaction of an agent This metaphor survived ancient culture and was integrated into mainstream Christianity by early Catholic theologians as Ambrose of Milan^[16] to modern Protestant theologians such as Karl Barth^[17] to attribute natural evil to God in explaining God's omnipotence over the universe. Christianity ( Greek Χριστιανισμός from the word Xριστός ( Christ)is a monotheistic Religion centered on the life and teachings Catholic is an Adjective derived from the Greek adjective '' / 'katholikos' meaning "whole" or "complete". Theology is the study of a god or the gods from a religious perspective Saint Ambrose (c 338 &ndash 4 April 397) was a bishop of Milan who became one of the most influential ecclesiastical figures of the fourth century Protestantism refers to the forms of Christian faith and practice that originated in the 16th century Protestant Reformation. Theology is the study of a god or the gods from a religious perspective Karl Barth ( May 10, 1886 &ndash December 10, 1968) (pronounced "bart" a Swiss Reformed theologian was one Natural evil (also known as surd evil) is the result of any event perceived to be morally negative and that is not caused by the action or inaction of an agent God is the principal or sole Deity in Religions and other belief systems that worship one deity. Omnipotence ( Omni Potens: "all Power " is unlimited power The Universe is defined as everything that Physically Exists: the entirety of Space and Time, all forms of Matter, Energy

Meanings evolved from use of these terms in the ancient languages. In many European languages, "right" is not only a synonym for correctness, but also stands for authority and justice: German and Dutch recht, French droit, Spanish derecho; in most Slavic languages the root prav is used in words carrying meanings of correctness or justice. The German language (de ''Deutsch'') is a West Germanic language and one of the world's major languages. Dutch ( is a West Germanic language spoken by around 24 million people 22 million of which are from the Netherlands, Belgium and Suriname French ( français,) is a Romance language spoken around the world by 118 million people as a native language and by about 180 to 260 million people The Slavic languages (also called Slavonic languages) a group of closely related Languages of the Slavic peoples and a subgroup of Indo-European languages Being right-handed has also historically been thought of as being skillful: the Latin word for right-handed is dexter, as in dexterity; indeed, the Spanish term diestro and the Italian's destro, mean both "right-handed" and "skillful". Latin ( lingua Latīna, laˈtiːna is an Italic language, historically spoken in Latium and Ancient Rome. Italian ( or lingua italiana) is a Romance language spoken by about 63 million people as a First language, primarily in Italy. In Irish, "deas" means "right side" and "nice". "Ciotóg" is the left hand and is related to "ciotach" meaning "awkward"^[18]; in French, "gauche" means "left" and is also a synonym of "maladroit", meaning "clumsy". Same for the Italian "maldestro" and the Dutch word "links".

Meanwhile, the English word sinister comes from the Latin word sinister, which originally meant "left" but took on meanings of "evil" or "unlucky" by the Classical Latin era. Classical Latin is the form of the Latin language used by the ancient Romans in what is usually regarded as "classical" Latin literature. Alternatively, sinister comes from the Latin word sinus meaning "pocket": a traditional Roman toga had only one pocket, located on the left side for the convenience of a right-handed wearer. This article is about the aviation term for the Roman garment see Toga. The contemporary Italian word sinistra has both meanings of sinister and left. Italian ( or lingua italiana) is a Romance language spoken by about 63 million people as a First language, primarily in Italy. The Spanish siniestra has both, too, although the 'left' meaning is less common and is usually expressed by izquierda,^[19] a Basque word. Basque ( native name: euskara) is the Language spoken by the Basque people who inhabit the Pyrenees in North-Central Spain In Portuguese, the most common word for left-handed person, canhoto, was once used to identify the devil, and canhestro, a related word, means "clumsy". Portuguese ( or língua portuguesa) is a Romance language that originated in what is now Galicia (Spain and northern Portugal.

The left side is often associated with awkwardness and clumsiness. The Dutch expression "twee linkerhanden hebben" and the Bulgarian expression "dve levi ratse" ("to have two left hands") both mean being clumsy. The English phrase, to have "two left feet" means to be bad at dancing. As these are all very old words/phrases, they support theories indicating that the predominance of right-handedness is an extremely old phenomenon.

In ancient China, the left has been the "bad" side. The adjective "left" (左 Mandarin: zuǒ) means "improper" or "out of accord". For instance, the phrase "left path" (左道 Mandarin: zuǒdao) stands for illegal or immoral means.

In Norwegian, the expression venstrehåndsarbeid (left-hand work) means "something that is done in a sloppy or unsatisfactory way". Norwegian ( norsk) is a North Germanic Language spoken primarily in Norway, where it is an official language Additionally, one of the Norwegian words for left-handed, "keivhendt", comes from Norwegian words meaning wrong handed or not straight handed.

The Hungarian word balfácán means twit. Hungarian ( magyar nyelv) is a Uralic language (more specifically a Ugric language) unrelated to most other languages in Europe. (Bal means left and fácán is for pheasant. ) Other synonyms are balfék and balek. However all these are euphemistic versions of the original vulgar word balfasz, combining "bal" and the vulgar name of the male genitals fasz.

In Ireland left handedness is called a "ciotógach" (kitt-oog) which is Irish for left-handed. Ireland ( Irish: Éire, ˈeːrʲə is a country in north-western Europe. Irish (ga ''Gaeilge'' is a Goidelic language of the Indo-European language family originating in Ireland and historically spoken by the Irish. It is frequently used amongst native Irish people, e. g. "she gave him a slap of the ciotógach after he insulted her at the bar" the word ciotógach is not derogatory and is held with affection amongst left-handed people.

In some parts of the English-speaking world 'cack-handed' is slang for left-handed. The origin of this term is disputed, but some suggest it is derived from the Latin cacare, in reference to the habit of performing ablutions with the left hand, leaving the right hand 'clean'. ^[20] However, other source suggest that it is derived from the Old Norse word keikr, meaning "bent backwards". ^[21]

The common Australian slang for a left-handed individual is the term Molly-Dooker, whose origins cannot be ascertained for certain, but whose intention is overwhelming clear.

Amongst Muslims, and in some societies including India, it is customary to use the left hand for cleaning oneself with water after defecating. A Muslim (مسلم pronounced Muslim, not Muzlim) is an adherent of the Religion India, officially the Republic of India (भारत गणराज्य inc-Latn Bhārat Gaṇarājya; see also other Indian languages) is a country The right hand is commonly known in contradistinction from the left, as the hand used for eating.

Even the word "ambidexterity" reflects the bias. Ambidexterity is the state of being equally adept in the use of both right and left Appendages (such as the Hands) 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". Latin ( lingua Latīna, laˈtiːna is an Italic language, historically spoken in Latium and Ancient Rome. This bias is also apparent in the lesser-known antonym "ambisinistrous", which means "clumsy on both sides" and derives from the Latin root "sinister. In Lexical semantics, opposites are words that lie in an inherently incompatible binary relationship as in the opposite pairs male: female, long: short "^[22]

In Esperanto, the word "left" is rendered maldekstra, literally meaning "opposite of right. is by far the most widely spoken constructed International auxiliary language in the world " A left-handed person is a maldekstrulo. The prefix mal- does not mean "bad", but simply "opposite"; in fact, "generous" translates as malavara, meaning "opposite of greedy. " A neologism liva was not accepted by the speakers.

In Russian, "to stray left" is a euphemism for being unfaithful to a spouse or partner. Russian ( transliteration:,) is the most geographically widespread language of Eurasia, the most widely spoken of the Slavic languages

Southpaw

A left-handed individual may be known as a southpaw, particularly in a sports context. Sport is an Activity that is governed by a set of rules or Customs and often engaged in competitively It is widely accepted that the term originated in the United States, in the game of baseball. The United States of America —commonly referred to as the Baseball is a Bat-and-ball Sport played between two teams of nine players each ^[23] Ballparks are often designed so that right-handed batters are facing east, so that the afternoon or evening sun does not shine in their eyes. A baseball park, baseball stadium, or ball park / ballpark is the field of play in the game of Baseball and the spectator seating areas This means that left-handed pitchers are throwing with their south-side arm. In Baseball, the pitcher is the player who throwsthe baseball from the Pitcher's mound toward the Catcher to begin each play with the goal of However, the Oxford English Dictionary lists a non-baseball citation for "south paw", meaning a punch with the left hand, as early as 1848,^[24] just three years after the first organized baseball game. The Oxford English Dictionary ( OED) published by the Oxford University Press (OUP is a comprehensive Dictionary of the English

In boxing, someone who boxes left-handed is frequently referred to as southpaw. Boxing (sometimes also known as English boxing or pugilism) is a Combat sport in which two participants generally of similar weight, The term is also used to refer to a stance in which the boxer places the right foot in front of the left, so it is possible for a right-handed boxer to box with a southpaw stance. Most boxers, southpaw or otherwise, tend to train with sparring partners who adopt an orthodox stance which gives southpaws an advantage.

Some left-handed persons may find the term offensive, especially if the term is not used in the context of a players preferred hand in sports. This is partially due to the modern obscurity of the term outside of the Southern United States, where it is used more frequently than other areas, thus causing a perception of slander by those unfamiliar with the term.

Accessibility of implements and skills

Kitchen knives (1)symmetrical, (2)right-handed, (3)left-handed

Left-handed people are sometimes placed at a disadvantage by the prevalence of right-handed tools in society. Many tools and devices are designed to be comfortably used with the right hand. For example, (right-handed) scissors, a very common tool, are arranged so that the line being cut along can be seen by a right-handed user, but is obscured to a left-handed user. Furthermore, the handles are often molded in a way that is difficult for a left-hander to hold, and extensive use in such cases can lead to varying levels of discomfort. Most importantly, the scissoring or shearing action - how the blades work together (how they are attached at the pivot) - operates correctly for a right-hander, but a left-hander will tend to force the blades apart rather than shearing the target substance. ^[25]

The computer mouse is sometimes made to fit the right hand better. In Computing, a mouse (plural mice, mouse devices, or mouses) Many computer installations have the mouse placed on the right side, making it awkward for left-handers to use without moving the mouse to the other side of the keyboard. Some mouse drivers and operating systems allow the user to reconfigure the mouse buttons to reverse their functions. An operating system (commonly abbreviated OS and O/S) is the software component of a Computer system that is responsible for the management and coordination However, being left-handed does not always mean the person uses the mouse on a computer with the left hand; many left-handers can use the mouse right-handed because they learned it that way from the start. It can be said that this is an advantage as one can use the mouse with their non-dominant hand, leaving their left to do tasks such as taking notes uninterrupted.

While European-style kitchen knives are symmetrical, Japanese kitchen knives have the cutting edge ground asymmetrically, with ratios ranging from 70-30 for the average chef's knife, to 90-10 for professional sushi chef knives; left-handed models are rare, and usually must be specially ordered or custom made. There are a number of different types of Japanese kitchen knives. In Japanese cuisine, is Vinegared Rice, usually topped with other ingredients including fish various meats and vegetables ^[26]

The lack of left-handed tools and machines in many workplaces is not only a nuisance to many left-handers, but has actually placed them at peril. One example is the band saw, whose standard design is convenient for right-handers but encourages left-handers to pass their arms dangerously close to the cutting blade with every pass of the saw. A band saw uses a blade consisting of a band of toothed metal and may be powered by wind water steam electrical motor or animal power In fact, some factories have installed left-handed equipment after successful class-action lawsuits on behalf of left-handed employees.

Many well-intentioned companies have manufactured products with left-handers in mind, but have still failed to meet left-handers' needs. For instance, many companies have produced "left-handed scissors" by simply inverting the scissors' handles, making the grip work for the left-hander. Unfortunately, for scissors to function in a truly left-handed manner, their blades must also be mirror-inverted, without which the left-hander is forced to make a "blind cut" because the blade obscures the paper from view. Mundial and Fiskars are companies that have produced truly left-handed scissors, inverting both the blades and the handles. Mundial S/A Produtos de Consumo is a Brazilian manufacturing company The Fiskars Corporation ( is a metal and consumer brands company founded in 1649 at Fiskars Bruk (Fiskarsin Ruukki a locality in Pohja municipality

Left-handed adaptations have even bridged the world of music; guitars are often made especially for lefties, and there have even been inverted pianos where the deepest notes correspond to the rightmost keys instead of the leftmost. ^[27] Inverted trumpets are made, too, but at a considerably higher cost. The prevailing belief is that left-handed trumpeters aren't at a significant disadvantage; the French Horn, for example, is played with the left hand, yet most horn players are right-handed.

Left-handed golf clubs were one of the earlier, and well-accepted, manifestations of a special version of an implement; the most notable left-handed-playing participant being Phil Mickelson (he is naturally right-handed). Career summary Early years through college Mickelson was born in San Diego California and raised there and in Arizona.

Handwriting

It can be difficult for left-handed children to learn to write if the teacher does not take the student's left-handedness into account. In fact, even in the later 20th century, some UK schools were discouraging children from writing with their left hand, often seriously affecting the child's development (Hansard 1998). When properly done, left-handed writing is a mirror image to that of the right-hander, making the teaching process confusing (if right-handed) for the teacher of a left-handed student. The result is that many left-handed children learn to write with their hand curled around the pen so that it can meet the paper at the same angle as the right-hander, rather than simply tilt the paper the opposite way. Once this habit is formed, it is difficult to break. This curling of the hand results in the heel of the palm being placed behind the writing, forcing the writer to lift it off the paper and making the grip even more awkward. In addition, constantly lifting and replacing the hand over fresh ink often causes smudging, causing problems for many left-handed students, especially in exam situations. When the left hand is held correctly, it is below the writing, as is typical for right-handers.

However, left-handed people who speak Arabic, Persian, Urdu and Hebrew or any other right to left language, do not have the same difficulties with writing. Arabic (ar الْعَرَبيّة (informally ar عَرَبيْ) in terms of the number of speakers is the largest living member of the Semitic language Urdu ( ur '''{{Nastaliq اردو}}''' trans Urdū, historically spelled Ordu) is a Central Indo-Aryan language Urdu is a standardised The right to left nature of these languages prevents left-handers from running their hand on the ink as happens with left to right languages. Still, due to these alphabets being developed for right-handed people, the characters are still often more easily matched to a right-handed profile.

Firearms

The vast majority of firearms are designed for right-handed shooters, with the operating handle, magazine release, and/or safety mechanisms set up for manipulation by the right hand, and fired cartridge cases ejected to the right. Also, scopes and sights may be mounted in such a way as to require the shooter to place the rifle against his or her right shoulder. A left-handed shooter must either purchase a left-handed firearm (which are manufactured in smaller numbers and are generally more expensive and/or harder to obtain), shoot a right-handed gun left-handed (which presents certain difficulties, such as the controls being improperly located for them or shell cases being ejected towards their body), or learn to shoot right-handed (which may pose additional problems, primarily that of ocular dominance). Ocular dominance, sometimes called eye dominance or eyedness, is the tendency to prefer visual input from one Eye to the other Fortunately for left-handed people, modern guns feature more ambidextrous or right/left-handed reversible operating parts than their predecessors. Bullpup rifles are particularly problematic for lefties unless they can be reconfigured, since empty shells would be ejected fast and straight into the shooter's face and cheek potentially causing injury. Bullpup is a Firearm configuration in which the action and magazine are located behind the trigger Lever action and pump action firearms present fewer difficulties for lefties than bolt action weapons do. Lever-action is a type of Firearm action which uses a lever located around the trigger guard area (often including the trigger guard itself to load fresh cartridges A pump-action Rifle or Shotgun is one in which the handgrip can be pumped back and forth in order to eject and chamber a round of Ammunition. The term bolt action refers to a type of Firearm action in which the weapon's bolt is operated manually by the opening and closing of the breech with

Left-handedness and intelligence

In his book Right-Hand, Left-Hand,^[28] Chris McManus of University College London argues that the proportion of left-handers is rising and left-handed people as a group have historically produced an above-average quota of high achievers. University College London ( UCL) is a multi-faculty university institution based in the United Kingdom and a constituent college of the University of London He says that left-handers' brains are structured differently in a way that widens their range of abilities, and the genes that determine left-handedness also govern development of the language centers of the brain.

McManus also says that the increase in the 20th century of people identifying as left-handed could produce a corresponding intellectual advance and a leap in the number of mathematical, sporting, or artistic geniuses.

In 2006, researchers at Lafayette College and Johns Hopkins University in a study found that left-handed men are 15 percent richer than right-handed men for those who attended college, and 26 percent richer if they graduated. Lafayette College is a private Coeducational liberal arts and engineering college located in Easton, Pennsylvania, USA The wage difference is still unexplainable and does not appear to apply to women. ^[29]

Prevalence with age

In Britain, a study in the 1970s found that around 11 percent of men and women aged 15-24 were left-handed, compared to just 3 percent in the 55-64 age category. The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom, the UK or Britain,is a Sovereign state located ^[30] The study suggests that 'cultural pressures' for right-hand use were prevalent in the industrial societies in the 18th and 19th centuries (with the advancement of mass literacy), and that those pressures were only significantly relaxed in the 'later decades' of the 20th century. The study also refers to tests on medieval skeletons that show evidence of hand-usage similar to today's, which suggests that hand-prejudice was not always part of UK society.

Right-Hand, Left-Hand author Chris McManus also suggests a number of factors that may have led to the modern increase in left-hand usage:

• Left-handers suffered severe prejudice during the 18th and 19th centuries and it was often "beaten out" of people
• In adulthood, left-handers were often shunned by society, resulting in fewer marrying and reproducing
• As prejudice declined in the 20th century, the number of natural left-handers who stayed left-handed increased
• The rising age of motherhood contributed as, statistically, older mothers are more likely to give birth to left-handed children.

Statistics show that older people are less likely to be left-handed than their younger counterparts — the percentages of left-handed people sharply drop off with increased age. In the U. S. , 12 percent of 20 year olds are left-handed, while only 5 percent of 50 year olds and less than 1 percent of people over 80 are. ^[31]

A study^[32] published in 1991 claimed that these statistics indicate that left-handed people's lifespans are shorter than those of their right-handed counterparts by as much as 9 years. The authors suggested that this may be the result of left-handed people being more likely to die in accidents as a result of their "affliction", which renders them clumsier and ill-equipped to survive in a right-handed world. Many subsequent studies have shown no evidence that left-handed people have reduced longevity compared to right-handed people^{[33][34][35][36][37]}

According to The Left-Hander Syndrome^[38] most people were only forced to write with their right hand and allowed to continue being left-handed in most other respects indicating that the decline in older left-handers is not from being forced or switching in later life. The word longevity is sometimes used as a synonym for " Life expectancy " in Demography.

Dory Previn wrote a song in which she explains that she was born left-handed but nuns in her school "broke her out of it"; later in life, she went back to using her left hand she said "I went back to using my left, my natural hand," and discovered her musical talent, among other things. Dory Previn, née Dorothy Veronica Langan (born 22 October 1925 or 1929 is an American Lyricist, Singer-songwriter and Poet A Nun is a Woman who has taken special vows committing her to a religious life

Nuns are often associated with training left-handers to write with their right hand. However, this practice was common in both religious and non-religious schools. The training was due to the difficulty left-handers had writing with liquid ink or fountain pens. An ink is a Liquid containing various Pigments and/or Dyes used for coloring a surface to produce an Image, text, or A fountain pen is a Pen that contains a reservoir of water-based liquid ink. When writing with these pens, the side of the left-hander's hand would smear the writing as it passed over the newly-written words. Fountain pens have widely been replaced by the ballpoint pens, although traditional teaching methods still stipulate the use of fountain pens.

Left-handedness in sports

There are many left-handers in sports; however, a written rule in polo states that one must not hold a stick in his or her left arm. Polo is a team sport played outdoors on Horseback in which the objective is to score goals against an opposing team ^[39] There are very few left-handed professionals in polo; all are required to use their right hand. Jai-Alai is another sport where left-handed play is forbidden. Jai alai (ˈhaɪəlaɪ in English and jaɪɑlaɪ or xaɪɑlaɪ in Basque

In field hockey, right-handed play is effectively required (though not explicitly so) because one rule states that the ball cannot be played with the back of the stick and left hand sticks are not allowed. Field hockey is a Team sport in which players attempt to score goals by hitting the Ball across the pitch with a stick The reason for this is because when attempting to tackle the opponent's stick, the left-hander would have to go through his/her legs,^[40] while another specifies that the stick be flat on its left side,^[41] which would be the "natural" side for a right-handed player, but when playing with the stick in one hand (playing reverse), this can give an advantage back to the left-handers. Having all players play with the same handedness is essential to keeping field hockey a non-contact sport: a left-hander and a right-hander competing for the ball would tend to collide. Interestingly, in the sport of ice hockey, there are many more left- shooters. Ice hockey, often referred to simply as hockey, is a team Sport played on Ice. When shooting, the player's less dominant hand is in the middle of the stick, and the dominant hand is at the top of the stick. When skating fast, or stretching to reach a far away puck, a player will often use only the top hand on the stick. The majority of right-dominant players shoot left-handed, and likewise, the majority of left-dominant players shoot right, allowing them to use their dominant hand when wielding the stick one-handed. The majority of goaltenders also catch with their left hand. In Canada, left-handed children are encouraged to play with a right-handed shot, and this puts their dominant hand on the top of the stick, which strengthens stick-handling skills. However, in the United States, lefties are encouraged to play left-handed; this is because of a perceived advantage at shooting and vision on the ice.

In fencing, a right-handed fencer might be more accustomed to facing another right-handed fencer simply because being right-handed is more common. Fencing is the art of armed Combat involving Cutting, Stabbing, or slapping bludgeoning Weapons directly manipulated by hand A left-handed fencer might also be more accustomed to facing a right-handed opponent for the same reasons. Therefore, when a right-handed fencer faces a left-handed opponent, the right-hander is not as used to fighting a left-hander as the left-hander is used to fighting a right-hander, causing a noticeable advantage. The same advantage may be present for most one-on-one or face-to-face sporting events.

Baseball is particularly suited to left-handed players for several reasons: left-handed batters are already a step or two closer to first base in their batter's box before they even hit the ball and are more likely to beat out close plays, although a left-handed hitter faces third base and has to pivot before running to first. Baseball is a Bat-and-ball Sport played between two teams of nine players each Many baseball parks have shorter right field fences which gives left-handed sluggers a few more home runs that would otherwise be outs. And finally, most pitchers are right-handed which gives the left-handed hitter a better angle to see the ball and causes curve and sliding pitches to move towards them, rather than away (right-handed batters are similarly advantaged against left-handed pitchers. ) That is why a good switch hitter is considered valuable. In Baseball, a switch-hitter is a batter who is able to hit from both the right and left sides of the plate Also, it is generally preferred (but not required) that first-basemen be left-handed to give them a better tagging angle on pick-off moves and more so because on most balls hit in the field of play, their gloved right hand would be on its forehand as opposed to the backhand. Left-handed fielders almost never play third base, shortstop, or second base, however, because the throwing position towards first base is awkward for a lefty. Catchers are virtually always right-handed as well, because it is difficult to throw to third base in an attempt to catch a base-stealer since a southpaw would have to pivot to the left to get in position for the throw rather than deliver a quick snap with the right hand. The only career catcher to ever throw with his left hand was Jack Clements, who caught for 17 years in the 19th century. John J "Jack" Clements ( July 24, 1864 – May 23, 1941) was a Baseball player who played for 17 seasons in the Major A left-handed pitcher naturally faces toward first base, and thus can easily keep an eye on a runner trying to steal second. However, a right-handed pitcher has a more natural body movement in throwing the ball towards first base, when attempting to pick off the runner. First-baseman Charlie Grimm was known as "baseball's only left-handed banjo player"--rare indeed when one considers how difficult it is to play most stringed musical instruments left-handed. First base, or 1B, is the first of four stations on a Baseball diamond which must be touched in succession by a baserunner in order to score a run Charles John Grimm ( August 28 1898 - November 15 1983) nicknamed "Jolly Cholly" was an American First baseman The banjo is a Stringed instrument developed by enslaved Africans in the United States, adapted from several African instruments

In football (soccer), left-handed players are often more skilled at playing with the left foot (though being left-handed does not necessarily result in being left-footed), which makes them valuable as they can play better on the left side of the field than right-handed players. Association football, more commonly known as football or soccer, is a Team sport played between two teams of eleven players and is widely considered Boardsports such as Skateboarding, Surfing, Wakeboarding and Snowboarding essentially involve the body's being oriented sideways relative to its overall A famous example of a left-handed football player, who also plays with his left foot is the Argentinian superstar Lionel Messi. Lionel Andrés Messi (born June 24 1987 in Rosario) is an Argentine footballer who plays for FC Barcelona in La Liga.

In tennis, left-handers impart spin on the ball that is opposite of that which a right-hander would hit. Tennis is a sport played between two players ( singles) or between two teams of two players each ( doubles) As a result, right-handed players (who are accustomed to playing right-handers) have difficulty dealing with a left-hander's shots which curve in a direction opposite to what they are accustomed to facing. Rafael Nadal, despite being right-handed, plays left-handed tennis after being encouraged to do so by his coach for this very reason. Rafael Nadal Parera (rafaˈel naˈðal (born June 3 1986 is a Spanish professional Tennis player who has been ranked World No

In American football, the most famous left-handed players are usually quarterbacks, such as Kenny Stabler, Michael Vick, Mark Brunell, Steve Young, Boomer Esiason, Matt Leinart, and Jim Zorn. American football, known in the United States and Canada simply as football, is a competitive Team sport known for mixing strategy with Ken "Kenny" Michael Stabler (born December 25, 1945 in Foley Alabama) nicknamed "The Snake", is a former American Michael Dwayne Vick (born June 26 1980 in Newport News Virginia) is a suspended National Football League (NFL Quarterback under contract Mark Allen Brunell (born September 17, 1970 in Santa Maria, California) is an American football Quarterback for the Steve Young (born Jon Steven Young on October 11, 1961 in Salt Lake City Utah) is a former Quarterback for the NFL's Norman Julius "Boomer" Esiason (born April 17, 1961) is a former American football Quarterback and current network Color commentator Matthew Stephen Leinart (born May 11, 1983) is an American football Quarterback (QB for the Arizona Cardinals of the National James Arthur "Jim" Zorn (born May 10, 1953 in Whittier, California) is the current American football Head coach Vick may be an exception though, since he is normally right-handed, but throws with his left, despite there being many right-handed quarterbacks who have had much NFL success. Donovan McNabb is normally left-handed, but throws with his right. Donovan Jamal McNabb (born November 25 1976 in Chicago Illinois) is an American football Quarterback for the Philadelphia Eagles of the

In basketball, left-handed players have a distinct advantage on both ends of the court. Basketball is a team Sport in which two teams of five active players each try to score points against one another by propelling a ball through a 10 feet (3 m On defense, it easier to play against a right-handed player since the defender typically angles the left side of his body towards the dribbler to both force him to dribble with his left hand, and to raise his own left hand in the event of a jumpshot. Conversely if that offensive player is left-handed, the standard defensive stance would favor them as they are not being forced to use their weaker hand. In fact, dribbling with the left hand is a highly valued skill in basketball for this very reason. When shooting, since the defender will typically raise his left hand to attempt the block the shot (since his left hand will be closer to the shooter's right-handed shot) a left-handed shooter will have more room to see the basket and attempt the shot.

In water polo, being left-handed allows a player to have an easier time shooting from the right side of the field, as having their shooting hand towards the middle of the field allows them to whip the ball around the keeper and into the upper left corner, a shot which a right-hander in the same position would find impossible. Water polo is a team water sport A team consists of six field players and one Goalkeeper. Also, when driving into the center from the right side, a left-handed player can take a dry pass and immediately shoot, whereas a right-handed player would require a wet pass and have to try and chip the goalie on a pop shot. This is why many teams like to have left-handed players, and why they tend to only play on the right (right-handed players have all similar advantages on the left side of the pool).

Boxing appears to be something of an exception to the rule that being a southpaw confers an advantage. Boxing (sometimes also known as English boxing or pugilism) is a Combat sport in which two participants generally of similar weight, Until Karl Mildenberger fought Muhammad Ali in 1966, there had not been a southpaw challenger for the heavyweight title since James J. Corbett, aka "Gentleman Jim" in 1892, and there have only been three southpaw heavyweight title holders since then: Michael Moorer, Corrie Sanders, and the current WBA heavyweight champion Ruslan Chagaev. Karl Mildenberger (born Kaiserslautern, 23 November 1937) is a retired German Heavyweight boxer. Biography Early life Cassius Clay Jr was born on January 17 1942 James John "Gentleman Jim" Corbett ( September 1, 1866 in San Francisco California – February 18, 1933 in Bayside Michael Lee Moorer (born November 12 1967) is a boxer who has been a world champion in the light heavyweight and heavyweight divisions Cornelius Johannes Sanders (born on January 7, 1966 in Pretoria South Africa) is a South African boxer The World Boxing Association (WBA is a Boxing organization that sanctions official matches and awards the WBA world championship title at the professional level Ruslan Chagaev (Ruslan Chagayev Руслан Шамилович Чагаев Руслан Шамил улы Чагаев|Ruslan Şamil ulı Çağayıv born October 19 However, it is worth distinguishing between the southpaw stance and being left-handed, because some trainers will train a naturally left-handed boxer to fight in an orthodox stance, not merely for convenience but because there may be an advantage in having the jab delivered with the stronger hand. A jab is one of the four main punches used in boxing Several variations of the jab exist but every jab shares these characteristics while in a boxing stance, the lead Hence a number of boxers who fought in an orthodox stance may have been converted left-handers.

In cricket, left-handed players have thrived over the years. Cricket is a bat-and-ball team Sport that originated in England and is now played in more than 100 countries Many technically sound batsmen have been left-handed. As of mid 2006, each and every of the Test playing nations have at least one left-handed batsman in their side. One of the reasons for this is that having a mix of right and left-handers tends to disrupt the bowler's accuracy, because when both a right-handed batsman and a left-handed batsman are batting, the bowler must adjust the line he is bowling when the batsmen change ends. Some famous left-handed cricketers include yesteryear greats like Graeme Pollock, Allan Border, David Gower, Gary Sobers and Wasim Akram; and contemporary greats Brian Lara, Saeed Anwar, Sourav Ganguly, Sanath Jayasuriya, Adam Gilchrist, Graeme Smith, Mike Hussey and Matthew Hayden. Robert Graeme Pollock (born 27 February 1944 in Durban, Natal) was a South African cricketer Allan Robert Border, AO (born 27 July 1955 is a former Australian Cricket captain David Ivon Gower, OBE (born April 1, 1957) is a retired Cricket player and current cricket broadcaster Sir Garfield St Auburn Sobers, AO (born 28 July 1936 in Bridgetown, Barbados) often known as Garry Sobers (though earlier in his life he preferred Wasim Akram ( Urdu: وسیم اکرم) (born June 3, 1966 in Lahore, Punjab) is a former Pakistani Cricketer Brian Charles Lara (born 2 May 1969 ( nicknamed, "The Prince of Port-of-Spain" "The Prince of Trinidad" or simply "The Prince" is a Saeed Anwar ( Urdu: سعید انور born September 6 1968) in Karachi, Pakistan, is a former Pakistani opening Sourav Chandidas Ganguly (সৌরভ গাঙ্গুলী ( (born 8 July 1972 is an Indian Cricketer and former former captain of the Indian national Sanath Teran Jayasuriya (born 30 June, 1969 in Matara) is a Sri Lankan Cricketer The All-rounder has been a member Adam Craig Gilchrist (born 14 November 1971 Nicknamed Gilly or Church, is a retired Australian international Cricketer -->He Graeme Craig Smith (born 1 February 1981 in Johannesburg) is a South African Cricketer and the current captain of the South African cricket team Michael Edward Killeen Hussey (born 27 May 1975 Morley Western Australia) is an Australian Cricketer. Matthew Lawrence Hayden (29 October 1971 is an Australian Cricketer. It is also well-known that Sachin Tendulkar and Darren Gough both write left-handed. Darren Gough (born September 18 1970, Monk Bretton, near Barnsley, South Yorkshire) is a retired English Cricketer However, many of these players are actually right-handed but bat left-handed.

In ten-pin bowling, left-handed bowlers often need to buy bowling shoes with a sliding sole on the right shoe (the right foot is the one used for release), unless both right and left shoes have sliding soles. Ten-pin bowling is a competitive Sport in which a player (the “bowler” rolls a Bowling ball down a wooden or synthetic ( Polyurethane There is a stereotype that left-handers start from the outside of the lane and do a stroker style release. In the sport of Ten-pin bowling there are many different ways in which to deliver (known as a "throw" or "roll" the Bowling ball in order to advance it toward Left-handers also have a vast advantage during league and tournament play in ten-pin bowling. As many games are bowled on the same lanes, the oil is dried up and smeared around. This happens less on the left side of the lane as there are, typically, less bowlers bowling left-handed. Left-handed bowlers include Rafael Nepomuceno, Earl Anthony, Parker Bohn III, Jason Couch and Patrick Allen. Rafael "Paeng" Nepomuceno (born January 30, 1957 in Manila) is a Filipino and is a 6-Time World Bowling Champion and is Earl Roderick Anthony ( April 27 1938 - August 14 2001) was a left-handed American professional bowler. Parker Morse Bohn III (born July 13, 1963 in Jackson Township New Jersey) is a left-handed American professional bowler and has been Jason Couch is one of the top bowlers on the Professional Bowlers Association (PBA tour

In Ultimate, being left-handed can throw off a defender who is more accustomed to defending a right-hander. Ultimate (often called Ultimate Frisbee in reference to the trademarked brand name) is a non-contact Team sport played with a 175 gram Flying This is more noticeable at the amateur level. The usual right-sided guard blocks a right-handed player's backhand, which can nullify beginners who have yet to develop a forehand or hammer throw. A lefty, however, can easily throw around a right-sided guard, as their backhand is wide open. Furthermore, a left-hander can be more readily able to throw around their marker's body (also known as 'breaking the mark') on the forehand side due to being able to throw from a more off-balanced position and the defense not setting a mark symmetrically on each side of the body. This has the result of opening up the pitch for their receivers.

Minor sports where left-handedness is a significant advantage include Eton Fives, where the buttress is on the left, the ideal serve placing the ball at the bottom corner - almost impossible for a right-handed player to reach. Eton Fives, one derivative of the British game of Fives, is a hand-ball game similar to Rugby Fives, played as doubles in a three-sided court Another is Real (Royal) Tennis, in which the serve along the penthouse is far easier with the left hand than with the right. Real tennis is the original racquet sport from which the modern game of lawn tennis or Tennis, is descended

Left-handedness in music

In music, guitar great Jimi Hendrix played a right-handed Fender Stratocaster strung upside down to accommodate his left-handedness. James Marshall Hendrix (born Johnny Allen Hendrix) (November 27 1942 – September 18 1970 was an American Guitarist, Singer and Songwriter The Fender Stratocaster, often referred to as the Strat, is a model of Electric guitar designed by Leo Fender, George Fullerton and Freddie Tavares Upon meeting Robert Fripp, leader of King Crimson (of whose music Hendrix had become an avid fan), Hendrix asked him to shake his left hand. Robert Fripp (born 16 May 1946 in Wimborne Minster, Dorset, England) is a Guitarist, Composer and a Record King Crimson is a Progressive rock band founded by guitarist Robert Fripp and drummer Michael Giles in 1969 ^[42] Although left-handed, Fripp plays guitar right-handed. Paul McCartney of The Beatles is left-handed; when he first played for John Lennon, he played Lennon's right-handed guitar upside-down. Sir James Paul McCartney, MBE (born 18 June 1942 is an English rock Singer, Bass guitarist songwriter Composer, The Beatles were a pop and rock band from Liverpool, England formed in 1960 John Winston Ono Lennon, MBE (born Mark Knopfler and David Knopfler are left-handers who play regular right-handed guitars. Mark Knopfler OBE (born August 12 1949 Glasgow, Scotland) is a British Guitarist, Singer, Songwriter, David Knopfler (born December 27 1952 in Glasgow) is a British guitarist pianist drummer singer and songwriter who was born in Billy Ray Cyrus and Dan Seals are notable county music singers who play guitar left-handed. Billy Ray Cyrus (born William Ray Cyrus; August 25 1961 is a Grammy Award -nominated American Country music singer songwriter and actor from Flatwoods Dan Wayland Seals (born February 8 1948 in McCamey Texas) is an American musician Freddie Mercury, pianist, song writer and lead singer of Queen was left-handed. Freddie Mercury (born Farrokh Bulsara; 5 September 1946 – 24 November 1991 was a Zanzibar -born British Musician, best known as the lead Queen were an English rock band formed in 1970 in London by guitarist In India where Freddie was educated during his early childhood, parents and educators discouraged the use of the left hand, so Mercury learned to write and perform other tasks equally well with his right hand. Nirvana front man Kurt Cobain was a well known left-handed guitarist. Kurt Donald Cobain (February 20 1967 – c April 5 1994 was an American musician who served as lead singer, Guitarist, and songwriter for the Seattle Albert King and BB King are also left-handed; however the latter plays right sided guitars while the former usually played a Flying V strung for a right-hander but with a left-handed stance (upside down). Albert King ( April 25 1923 &ndash December 21 1992) was an American Blues Guitarist and Singer B B King (born Riley B King, September 16 1925 is an American Blues Guitarist and Singer-songwriter. The Gibson Flying V is an Electric guitar model first released by Gibson in 1958. Niccolò Paganini, violinist and composer, was left-handed. Niccolò Paganini ( October 27, 1782 &ndash The classical pianist Glenn Gould was left-handed. Glenn Herbert Gould At a young age he reportedly behaved differently from typical children at the piano he would strike single notes and listen to their long decay Ringo Starr of The Beatles is also left-handed, even though he plays a right-handed drum set, which gives him a distinct style of drumming. Ringo Starr, MBE (born Richard Starkey on 7 July 1940 is an English Musician, Singer, Songwriter and Actor The Beatles were a pop and rock band from Liverpool, England formed in 1960 Dom Howard of Muse is also left handed, and plays on a left handed drum kit. Dominic James Howard, or sometimes Dom Howard (born 7 December, 1977 in Stockport, England) is the Drummer for the Muse are Despite this, Gallagher plays the guitar right-handed as he says this is the 'only thing' his right hand is good at. ^[43] Zacky Vengeance of Avenged Sevenfold, Dick Dale, Colie Brice, Doyle Brahmhall III plays guitar left-handed. Zacky Vengeance (born Zachary James Baker on December 11 1981 is the rhythm guitarist and back up vocalist for the band Avenged Sevenfold. Avenged Sevenfold is an American Hard rock band formed in 1999 in Huntington Beach California. Dick Dale (born Richard Anthony Monsour on May 4, 1937, in Boston, Massachusetts) is a Surf rock guitarist,

Left-sidedness

Studies show that left-handedness does not necessarily correspond with "left-sidedness" (such as using your left foot to kick with), though most left-handed people tend to have "left-sidedness". The same effect holds with ocular dominance. It has also been found that people have dominant sides of the body, such as the eye, foot, and ear.

Possible effects in humans on thinking

There are many theories on how being left-handed affects the way a person thinks. The word theory has many distinct meanings in different fields of Knowledge, depending on their methodologies and the context of discussion. One theory divides left- and right-handed thinkers into two camps: visual simultaneous vs. linear sequential. ^{[44][45][46][47]}

According to this theory, right-handed people are thought to process information using a "linear sequential" method in which one thread must complete its processing before the next thread can be started.

Left-handed persons are thought to process information using a "visual simultaneous" method in which several threads can be processed simultaneously. Another way to view this is such: Suppose there were one thousand pieces of popcorn and one of them was colored blue. Right-handed people—using the linear sequential processing style—would look at the popcorn one at a time until they encountered the blue one. The left-handed person would spread out the pieces of popcorn and look at all of them to find the one that was blue. A side effect of these differing styles of processing is that right-handers need to complete one task before they can start the next. Left-handers, by contrast, are capable and comfortable switching between tasks. This seems to suggest that left-handed people have an excellent ability to multi-task, and anecdotal evidence suggests that there are more creative stems due to this ability to multi-task.

Right-handed people process information using "analysis", which is the method of solving a problem by breaking it down to its pieces and analyzing the pieces one at a time. By contrast, left-handed people process information using "synthesis", which is the method of solving a problem by looking at the whole and trying to use pattern-matching to solve the problem. ^[47]

The hypothesis that left-handed people are predisposed to visual-based thought has been validated by a variety of evidence. In the 2004 book Brains That Work a Little Bit Differently^[48], researchers Allen D. Bragdon and David Gamon, Ph. D. , briefly described some of the current research on handedness and its significance. "Handedness researchers Coren and Clare Porac have shown that left-handed university students are more likely to major in visually-based, as opposed to language-based subjects. Another sample of 103 art students found an astounding 47 percent were left- or mixed-handed. " [page 76]

Ultimately, being left-handed is not an all-or-nothing situation. The processing styles operate on a continuum where some people are more visual-simultaneous and others are more linear-sequential.

See also

• Right-handed
• Handedness
• Laterality
• Chirality (chemistry)
• Chirality (mathematics)
• Chirality (physics)
• The Tale of Cross-eyed Lefty from Tula and the Steel Flea
• Geschwind-Galaburda Hypothesis
• Situs inversus
• Handedness and sexual orientation

References

External links

• - A site containing useful facts, instructions, news, scholarship info and products for left handers.
• Lefties Have The Advantage In Adversarial Situations, ScienceDaily, April 14, 2006. Events 43 BC - Battle of Forum Gallorum: Mark Antony, besieging Julius Caesar 's assassin Decimus Junius Brutus in Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar.
• Science Creative Quarterly's overview of some of the genetic underpinnings of left-handedness
• Quirks & Quarks June 10, 2006 (CBC radio documentary on left-handedness including interviews with four scientists holding different views on the determinants of handedness)
• A left-handed senior citizen recalls the emotional torment he faced at a New York public school in the 1920s. (Audio slideshow)
• Famous Left-Handers
• Schwartz, Alyssa (2005). "Lefties face increased breast cancer risk," C-Health News, 30 September.
• Scans may 'cause brain changes', BBC News.
• Hansard (1998) ‘Left-handed Children’, Debate contribution by the Rt Hon. Mr. Peter Luff (MP for Mid-Worcestershire), House of Commons, 22 July.