Handedness defines which hand a person uses to perform most activities. This dominant hand is also evidence of which hemisphere of the brain determines a person’s actions. Even though left-handed people are much rarer than right-handed people in percentage terms, there is now an increased awareness of the special needs of people with dominant left handedness.
What is handedness?
Handedness defines which hand a person uses to perform most activities. This dominant hand is also evidence of which hemisphere of the brain determines a person’s actions. A person’s handedness is understood to be his or her dominant hand. This is the hand with which the person performs all difficult and demanding tasks – from writing to brushing teeth to sewing or precise cutting. This is the right hand in the majority of people. Only about 10 to 15 percent of the population are left-handed, meaning they naturally have a handedness that makes the left hand the dominant hand. This handedness also varies in degree: While some left-handers use their left hand exclusively, others use it for all activities except writing, for example. Equal use of both hands is also common. Science cannot yet provide an answer to the question of why handedness is so unequally distributed among people. One thing is certain, however: handedness is also an expression of the dominant hemisphere of a person’s brain. Since there is a crossover effect, the right hand is controlled by the left hemisphere of the brain and the left hand by the right hemisphere. Therefore, in right-handed people, the left hemisphere of the brain is considered dominant, and in people with left handedness, the right hemisphere of the brain is dominant.
Function and task
Handedness has many advantages for us humans. The specialization of the two brain hemispheres can probably be explained evolutionarily by the fact that this avoids competition between the two brain hemispheres. Concentration on one side also ensures that particularly high precision can be achieved in manual tasks. It is not yet scientifically explainable why handedness in humans is predominantly expressed in the form of a dominant right hand. The rarely occurring dominance of the left hand is not accompanied by a mirror-inverted structure of the hemispheres in the brain. In the majority of right- and left-handers, for example, the speech center is located in the left hemisphere. Thus, handedness has hardly any effect on language development. What the handedness does have an enormous effect on, however, is motor skills: In right-handers, motor skills are primarily controlled by the left hemisphere, in left-handers by the right. Motor skills are responsible, for example, for abilities such as writing or delicate manual work. Through targeted retraining, however, it is possible to have individual skills, such as writing, controlled by the non-dominant hemisphere of the brain. In this way, especially in past decades, many naturally left-handed people were retrained to write with the right hand. However, this does not result in a complete reorganization of the brain. Natural handedness is usually evident in many other activities – from sports to creative work to everyday routines. Neurological studies of individuals whose handedness has been artificially retrained show that the formerly dominant hemisphere of the brain is still responsible for planning and controlling movements. In retrained left-handers, the right hemisphere remains responsible for organizing movements. The benefit of artificially retrained handedness is therefore controversial. When writing in German and similar languages, retraining has the advantage of avoiding tensions and unclean writing, because left-handers often have difficulties in this area, since writing is done from left to right. However, retraining handedness can also become a burden.
Diseases and ailments
Complaints due to their own handedness have especially left-handed people. They are often affected by tension, for example, when they have to use equipment that is actually designed for right-handers. However, if the handedness is retrained to avoid such problems, other complaints can be the result.For example, left-handers who have been retrained to use the right hand as their dominant hand often complain of psychological problems. Psychologists attribute symptoms such as poor concentration, memory problems, sleep problems, fear of failure and even bed-wetting to the retraining of handedness. For this reason, retraining is no longer as popular as it once was. Today, left-handers are encouraged to live out their innate handedness. The declining importance of skills such as handwriting contributes to this trend. After all, when it comes to typing on a keyboard or touchscreen, handedness is rather unimportant. At the same time, more and more products designed specifically for left-handers are becoming available. These range from left-handed scissors to folders and computer mice to gardening utensils and tools. Thanks to these developments, their handedness is less and less likely to be a debilitating element for left-handed people. Directly related to handedness also seems to be a person’s creativity. This is because a disproportionately large number of creative people are found among left-handers. Experts believe this is because the right hemisphere of the brain is responsible for creativity, body language, intuition and feelings. The left hemisphere, on the other hand, is responsible for language and logic. Depending on the expression of the individual handedness, the explanation for a person’s talents can therefore lie in this.
