File Name: the left hander syndrome the causes and consequences of left handedness .zip
- Left-Handed People in a Right-Handed World
- The Left-Hander Syndrome
- The Left-Hander Syndrome: The Causes and Consequences of Left-Handedness
- The Left-Hander Syndrome: The Causes and Consequences of Left-Handedness
The neural correlates of hand preference are still debatable, and the very few studies on the mechanisms of enforced change of handedness from left to right are all restricted to early childhood. We were able to address the question of retraining handedness in late adulthood for the first time, well outside the accepted critical period for brain plasticity, through a unique training utilizing the complex motor task of blind memory-guided drawing, in a totally blind, congenitally left-handed man. Ten hours of this Cognitive-Kinesthetic Drawing Training, which the author initially developed to drive neuroplasticity in blindness rehabilitation, was sufficient to generate a profound switch in the cortical lateralization of motor control.
Left-Handed People in a Right-Handed World
By Stanley Coren. At various times in history, left-handedness has been regarded as many things: a nasty habit, a social inconvenience, or a mark of the devil.
It has also been taken as a sign of neurosis, rebellion, creativity, artistic ability, musical ability, psychopathology, mental retardation, criminality, homosexuality, genius, sports proficiency, or empathy.
Our long fascination with handedness is shown by its mention in the Bible; references to it appear in some Egyptian tomb writings. The problem of handedness has caught the attention of many thinkers and scientists including Charles Darwin, Benjamin Franklin, William James, and Thomas Carlyle.
Over the past twenty years or so, researchers have shown that left-handedness is more than a minor difference. Increasingly we are coming to understand that left-handedness has social, educational, and psychological implications and affects many aspects of health, well-being, and even life span. This book focuses on all that distinguishes right- and left-handers.
It demonstrates that handedness is only one part of sidedness, which also includes footedness, eyedness, and earedness, and shows readers how to measure their own sidedness. The book answers some common questions such as: Where does handedness come from? Is it coded in the genes? Does it stem from social pressure?
Might it indicate some damage or injury? Is it related to the organization of the brain, and how? Further, the book examines the differences between left- and right-handers in terms of intelligence, personality, creativity, and a number of other domains.
Left-handers may be one of the last unorganized minorities in our society, with no collective power and no real sense of common identity. Yet they are a minority that is often discriminated against by social, educational, and religious institutions.
Social customs and even our language set the left-hander apart as different and probably bad. This book in some sense records a journey of exploration begun when a scientist came across a surprising set of research findings. The resulting program of investigation, which extended over more than ten years, led that scientist to the shocking conclusion that left-handers probably die younger than right-handers.
He also found that most risks to which left-handers are especially vulnerable have to do with the way in which the right-handed majority treats the unseen left-handed minority.
This scientist here offers ways in which the left-hander can be made both safer and more comfortable in a right-handed world. I would like to thank many people who helped me directly and indirectly in the preparation of this book. Colleagues Darrin Lehman and Peter Suedfeld made useful comments, both formal and informal, on parts of this manuscript.
Mike McKinnell did some of the figures for chapters 13 and My lovely wife Joan read through the entire manuscript for continuity and even had the psychological stamina to stay married to me throughout the writing process. I must, of course, also thank the Natural Sciences and Engineering Research Council of Canada and the Medical Research Council of Canada, who have funded my research over the past two decades.
Finally, my gratitude goes to my invaluable co-investigators over the years: Diane Halpern, Clare Porac, and Alan Searleman, to whom this book is dedicated. A neglected minority group constitutes about 10 percent of the present human population.
Like many other minority groups it has been subject to prejudice, humiliation, and discrimination—not on the basis of race, religion, age, or national origin, but simply on the basis of the hand that its members use for such everyday acts as brushing teeth or cutting food.
This group consists of left-handers. Right-handers might feel that words such as discrimination used with reference to left-handers are a bit overdone or melodramatic. I a right-hander certainly would have felt that way when I began researching the psychology and neuropsychology of handedness some twenty years ago. But through that research it became clear to me that most of us do have a set of often-unacknowledged attitudes toward left-handers that express themselves in condescension and even scorn.
For proof of negative attitudes toward left-handers we need go no further than our own language. The very word left in English comes from the Anglo-Saxon word lyft, which means weak or broken. Common phrases in the English language demonstrate a negative view of left-handedness. For instance, a left-handed compliment is actually an insult. A son from the left side of the bed is illegitimate.
A left-handed diagnosis is wrong, and left-handed wisdom is a collection of errors. To be about left-handed business is to be engaged in something unlawful or unsavory. Sailors speak of ships that are left-handed, meaning that they are unlucky or wrong in some way.
Someone talking about your sex life who calls you left-handed has labelled you a homosexual; bent to the left carries the same meaning. Not one positive phrase is to be found in the language surrounding left or left-handed. Right and Right-handed seldom seem to connote anything more than favoring the right hand for various activities.
A right-handed wife simply describes a married woman who favors the use of her right hand. In those few instances where there is any emotional content, right carries a positive connotation. One must not suppose that speakers of the English language have a unique dislike of left-handers.
The tendency appears to be universal. For example, in French the word for left is gauche, which also conveys the meanings crooked, ugly, clumsy, uncouth, and bashful. The word gauche has been taken over directly in English with its negative connotations intact.
A person who acts inappropriately in a social situation is said to be gauche. The German word for left-handed is linkisch, which also gets the dictionary definition of awkward, clumsy, and maladroit. The left-hander does no better in Spanish, where the word for left-handed is zurdo.
It is used in phrases such as no ser zurdo, which means to be very clever, but literally translates as not to be left-handed. A similar picture appears in Italian where a left-hander is mancino, which is derived from crooked or maimed mancus and is also used to mean deceitful or dishonest. The bad press of the left-hander in Italy, however, is a historical carry-over from the Latin, in which the word for left is sinister, closely related to the noun sinistrum, meaning evil.
Eastern European languages continue the tradition of denigrating left-handers. In Russian, to be called a left-hander levja is a term of insult. One variant of this term is used to refer to a black-marketeer, while from the same root comes the phrase na levo, meaning sneaky. The word for left in Polish is quite similar lewo ; it also conveys the idea of illegal, and is often used to refer to a sneaky or underhanded trick. Similarly, in Romany the language of the Gypsies we find bongo, also the term used to describe a crooked card game, a fixed horse race, or a wicked and dishonest person.
If a word meaning continues to endure, that fact suggests that the idea or usage has been generally accepted by the speakers of the language as correct and useful. Thus our language says that we feel that the left-handers are not a very nice group of people and that they are definitely wrong in many ways.
What is the origin of these negative attitudes? I doubt that handedness really entered my consciousness to any degree when I was a child. I knew that left and right were different, because I remembered my father telling a story about the problem of remembering which was which. The usual tactics of shouting I said left! Not that left foot, your other left foot! Exasperated, the sergeant resorted to a mnemonic or memory device.
He tied a piece of hay to the left foot of each man and resumed the march, shouting, Hayfoot, right, hayfoot, right, until the group finally mastered close-order drill and the concepts of left and right.
As a child I could distinguish left from right and knew that my right hand did most of the work, such as writing, putting food into my mouth, brushing my teeth, and holding tools. My left hand was merely the other one. Perhaps the first left-hander that I remember was my cousin Steve. Steve was a few years younger than me. Since his parents lived less than a city block from our house and the families frequently visited, I knew him pretty well, or at least I thought I did.
One night, at one of those large family dinners where everybody squeezes together around a table to eat, I found my cousin Steve seated next to me on my right side. Dinner started with bowls of hot soup. As we began to eat, because of the close quarters, disaster struck.
His sister Eleanor immediately barked, Stephen, you are so clumsy. You are always doing things like that! Two things were happening at that moment in my life. Second, I was being exposed to my first bit of negative propaganda about left-handers as my Aunt Sylvia buzzed around trying to clean Steve up, while muttering, Stephen, you really have to be more careful.
From across the table my Aunt Frieda advised, You really ought to teach him to eat with his right hand. The conversation continued for a while, as the family discussed whether Steve was simply an uncoordinated and awkward child, whether he was using his left-handedness as a means of getting attention, or whether he was simply being stubborn and intractable by not using his right hand. None of it was very complimentary. Today, from the perspective of a psychologist, I would say that I was beginning to form a stereotype about left-handers.
Stereotypes are impressions of whole groups of individuals. Stereotypes are based on a number of grouping principles. Notice in my examples that some group impressions were based upon nationality and others upon occupation, race, religion, sex, and age. Visible physical or behavioral characteristics play an important role in forming stereotypes.
Handedness, of course, involves visible behaviors that mark an individual as a member of the left or right group. An important prerequisite for stereotype formation is recognition of the characteristics that distinguish one group from another, a process called social categorization.
Up to the night of that dinner with my cousin Steve, for instance, I had been unaware that the characteristic of handedness defined a particular group.
Now, amid the sploshes of chicken soup, I had become aware of the differences associated with handedness. This stereotype was subsequently to be shaped in a negative way, on its way toward becoming a prejudice. Another important prerequisite for stereotype formation is development of a notion of us versus them. Psychologists refer to us as the ingroup, to which we belong, and them as the outgroup. For me, of course, the ingroup was right-handers, while the outgroup was left-handers.
The Left-Hander Syndrome
By Stanley Coren. At various times in history, left-handedness has been regarded as many things: a nasty habit, a social inconvenience, or a mark of the devil. It has also been taken as a sign of neurosis, rebellion, creativity, artistic ability, musical ability, psychopathology, mental retardation, criminality, homosexuality, genius, sports proficiency, or empathy. Our long fascination with handedness is shown by its mention in the Bible; references to it appear in some Egyptian tomb writings. The problem of handedness has caught the attention of many thinkers and scientists including Charles Darwin, Benjamin Franklin, William James, and Thomas Carlyle.
Skip to search form Skip to main content You are currently offline. Some features of the site may not work correctly. Handedness is one of the important human traits. If one looks around, one will notice that majority of the people are right-handed in this world. Still the lefthanders are not such a minority. Along with biology, in determination of hand preference, culture and religion also plays its role.
The Left-Hander Syndrome: The Causes and Consequences of Left-Handedness
In the current controversy over left-handedness as a marker for various pathological conditions, a number of published studies have failed to replicate associations between handedness and various risk factors reported by other investigators. This paper demonstrates that many of these studies have simply lacked the statistical power to do so. As demonstrated here, the problem usually consists of inadequate sample sizes for the conditions. A figure allowing estimation of statistical power under typical conditions associated with handedness research is provided.
The most common alternative to a genetic explanation of left-handedness is that sinistrality arises because of birth stress factors. In a sample of subjects, the association between birth stress and left-handedness was confirmed. More importantly, it was found the left-handed mothers are more likely to have birth-stressed offspring and that the presence of any left-handed sibling increases the likelihood of a history of birth stress in the proband.
The Left-Hander Syndrome: The Causes and Consequences of Left-Handedness
About 10 percent of the population is left-handed. The rest are right-handed, and there are also about 1 percent who are ambidextrous, which means they have no dominant hand. Not only are lefties outnumbered about 9 to 1 by righties, there are health risks that appear to be greater for left handers, too. A study published in the British Journal of Cancer examined hand preference and cancer risk. The study suggested that women with a dominant left hand have a higher risk of being diagnosed with breast cancer than women with a dominant right hand. The risk difference is more pronounced for women who have experienced menopause. However, researchers noted the study only looked at a very small population of women, and there may have been other variables that affected the results.
Look Inside. And in another century your proclivity might have gotten you accused of witchcraft. Any left-handed person, or the spouse, parent, or friend of one, will be captivated by this essential and eye-opening book.
Стратмор подошел еще ближе. Он хотел прикоснуться к ней, но не посмел. Услышав имя Дэвида, произнесенное вслух, Сьюзан дала волю своему горю. Сначала она едва заметно вздрогнула, словно от озноба, и тут же ее захлестнула волна отчаяния. Приоткрыв дрожащие губы, она попыталась что-то сказать, но слов не последовало. Не спуская со Стратмора ледяного взгляда, Сьюзан сделала шаг вперед и протянула к нему руку с зажатым в ней предметом. Стратмор был почти уверен, что в руке Сьюзан сжимала беретту, нацеленную ему в живот, но пистолет лежал на полу, стиснутый в пальцах Хейла.
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Шприц был наполнен тридцатью кубиками моющего средства, взятого с тележки уборщицы. Сильный палец нажал на плунжер, вытолкнув синеватую жидкость в старческую вену. Клушар проснулся лишь на несколько секунд. Он успел бы вскрикнуть от боли, если бы сильная рука не зажала ему рот. Старик не мог даже пошевелиться.
Стратмор покачал головой. - Я попросил его не звонить мне, пока он не найдет кольцо.