Handedness facts for kids
Handedness is the preference for using either the left or the right side of the body for certain things. People are described as left-handed or right-handed when they prefer to write with their left or their right hand. They may prefer the use of certain hands for certain tasks.
Most people are right-handed. Many prefer to use their right eye, right foot and right ear if forced to make a choice between the two). The reasons for this are not fully understood.
Ambidexterity is when a person has approximately equal skill with both hands and/or both sides of the body. True ambidexterity is very rare.
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Handedness and brain function
Handedness is caused by the lateralisation of brain function. Lateralisation is not only found in humans: it is found in many kinds of animals.
Handedness seems to follow from the brain hemisphere division of labor. In most people the left side of the brain controls speaking, and the left cerebral hemisphere of the brain controls the right side of the body. In 90-92% of all humans, the left hemisphere is the language hemisphere. Therefore right-handedness predominates. This theory predicts that left-handed people have a reversed brain division of labor.
In society
Many societies have tried to force right-handedness onto left-handed children ("forced laterality"). The general experience is that such attempts are not entirely successful, and cause distress. Writing is a case in point. A right-handed script moves towards the right, and the righthanded writer's hand reveals what has just been written, which is good feedback. When a left-handed person writes a right-handed script, their hand obscures (hides) what has just been written. That interferes with the natural visual feedback to the writer. So the way our alphabet is written, moving to the right, is better for right-handed writers. On the other hand, with a keyboard, handedness does not matter. This is why the issue of handedness is not so important now as it once was.
However, there are many tools which are usually made for right-handed people, and it may be difficult and more expensive to buy left-handed versions.
Handedness and early mankind
Physical anthropologists have pointed out that the human ability to throw weapons such as rocks and spears is quite notable. Chimpanzees have handedness, but their ability to throw is much less good. For protection, catching prey and for making tools, handedness is critical.
Other animals
Many other animals also have handedness. For example: elephants often have preferences for whether they swing their trunks to the left or the right. Honeybees have right antennas that are more sensitive to smells. Parrots can be left- or right-footed, and some don’t mind (they are ambidextrous). Animals as different as chickens and minnows like to look for food with one eye and look out for predators with the other. This seems to help them do two things at once.
Related pages
Images for kids
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Stenciled hands at the Cueva de las Manos in Argentina. Left hands make up over 90% of the artwork, demonstrating the prevalence of right-handedness
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Michael Vick, a left-handed American football quarterback, winds up to throw the ball to his teammate
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See also
In Spanish: Mano dominante para niños
