Laterality is the preference that most humans show for one side of their body over the other. Examples include right-handedness or left-footedness. It may also apply to other animals, or to plants. Human beings are defined variously in biological, spiritual, and cultural terms, or in combinations thereof. ... With regard to living things, a body is the integral physical material of an individual, and contrasts with soul, personality and behavior. ... A person who is right-handed is more dextrous with their right hand than with their left hand: they will write with their right hand, and probably also use this hand for tasks such as personal care, cooking, and so on. ... Regular stance, regular foot or simply regular refers to a skateboarder, surfer, snowboarder or wakeboarder who prefers riding with his left foot in front. ... Animalia redirects here. ...

Human laterality

The significant majority of humans are right-handed. Many are also right-sided in general (that is, they 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, but it is thought that because the left cerebral hemisphere of the brain controls the right side of the body, the right side is generally stronger; it is suggested that the left cerebral hemisphere is dominant over the right in most humans because in 90-92% of all humans the left hemisphere is the language hemisphere. A person who is right-handed is more dextrous with their right hand than with their left hand: they will write with their right hand, and probably also use this hand for tasks such as personal care, cooking, and so on. ... A human eye. ... For other uses, see Foot (disambiguation). ... Bat ears come in different sizes and shapes The ear is the sense organ that detects sound. ... The human brain as viewed from above, showing the cerebral hemispheres. ... For more specific information about the human brain, see its main article at human brain A sketch of the human brain by artist Priyan Weerappuli, imposed upon his sketch of the profile of Michaelangelos David In animals, the brain, or encephalon (Greek for in the head), is the control...

Human cultures are predominantly right-handed, and so the right-sided trend may be socially as well as biologically enforced. This is quite apparent from a quick survey of languages. The English word "left" comes from the Anglo-Saxon word lyft which means "weak" or "useless". Similarly, the French word for left, gauche, is also used to mean "awkward" or "tactless". Also, sinistra, the Latin word from which the English word "sinister" was derived, means "left". Interestingly, the Greek word for left is aristera, from which the English word "aristocrat" derived. Similarly, in many cultures the word for "right" also means "correct". The English word "right" comes from the Anglo-Saxon word riht which also means "straight" or "correct." The words "adroit" and "dextrous", both meaning skillful, come from the French droit and the Latin dexter respectively. Culture (from the [[Latin)) cultura stemming from colere, meaning to cultivate), generally refers to patterns of human activity and the symbolic structures that give such activity significance. ... The English language is a West Germanic language that originates in England. ... Old English (also called Anglo-Saxon) is an early form of the English language that was spoken in parts of what is now England and southern Scotland between the mid-fifth century and the mid-twelfth century. ... Latin is an ancient Indo-European language originally spoken in Latium, the region immediately surrounding Rome. ... The English language is a West Germanic language that originates in England. ... Old English (also called Anglo-Saxon) is an early form of the English language that was spoken in parts of what is now England and southern Scotland between the mid-fifth century and the mid-twelfth century. ... Latin is an ancient Indo-European language originally spoken in Latium, the region immediately surrounding Rome. ...

This linguistic and social bias is not restricted to European cultures: for example, Chinese characters are designed for right-handers to write, and no significant left-handed culture has ever been found in the world.

When a person is forced to use the hand opposite of the hand that they would naturally use, this is known as forced laterality, or forced dextrality. A study done by the Department of Neurology at Keele University, North Staffordshire Royal Infirmary suggests that forced dextrality may be part of the reason that the percentage of left-handed people decreases with higher age groups. ^[1]

Ambidexterity is when a person has approximately equal strength in both hands and/or both sides of the body. True ambidexterity is very rare. Although a small number of people can write competently with both hands and use both sides of their body well, even these people usually show preference for one side of their body over the other. However, this preference is not necessarily consistent for all activities. Some people may for example use their right hand for writing, and their left hand for playing racket sports and eating (See also: cross-dominance). Ambidexterity is the ability of being equally adept with each hand (or, to a limited degree, feet). ... Human right hand The hands (med. ... Scribe Writing Writing, in its most general sense, is the preservation and the preserved text on a medium, with the use of signs or symbols. ... People who are left-handed are more dextrous with their left hand than with their right hand: they will probably also use their left hand for tasks such as personal care, cooking, and so on. ... The following is a list of sports, divided by category. ... // For eat or EAT as an abbreviation or acronym, see EAT. In general terms, eating (formally, ingestion) is the process of consuming nutrition, i. ... Cross-dominance, also known as mixed-handedness, mixed dominance and cross laterality, is a motor skills manifestation in which a person not necessarily being truly ambidextrous favors one hand for some crucial and precise fine motor skill operations and the other hand for others tasks. ...

Also, it is not uncommon that people preferring to use the right hand prefer to use the left leg, e.g. when using a shovel, kicking a football, or operating control pedals. In many cases, this may be because they are disposed for left-handedness but have been trained for right-handedness. Shovels are usually designed to be used with either foot.

Approximate statistics are below: ^[2]

• Favoring right hand: 88.2%
• Favoring right foot: 81.0%
• Favoring right eye: 71.1%
• Favoring right ear: 59.1%
• Same hand and foot: 84%
• Same ear and eye: 61.8%

Clockwise and counter-clockwise

Main article: clockwise and counter-clockwise

Most humans that are right-handed prefer to draw their circles and stir beverages counter-clockwise. This is thought to have come about due to a dominant brain hemisphere. ^[3] A clockwise motion is one that proceeds like the clocks hands: from the top to the right, then down and then to the left, and back to the top. ...

Laterality in other animals

Laterality in animals is also called limb dominance. Most race tracks are run counter-clockwise, which favors right-side dominant horses, as they take a longer stride with the right foreleg, which helps them turn to the left. Trainers of left eye dominant horses may put a blinder on the left eye to encourage the horse to turn the head slightly to the left and to take a longer step with the right foreleg just as right-side dominant horses do. Parrots tend to favor one foot when grasping objects (for example fruit when feeding). Some studies indicate that most parrots are left footed. Polar bears generally kill their prey using their left paw. Some types of mastodon indicate laterality through the fossil remains having differing tusk lengths. Horse-racing is an equestrian sporting activity which has been practiced over the centuries; the chariot races of Roman times were an early example, as was the contest of the steeds of the god Odin and the giant Hrungnir in Norse mythology. ... A clockwise motion is one that proceeds like the clocks hands: from the top to the right, then down and then to the left, and back to the top. ... Binomial name Equus caballus Linnaeus, 1758 The horse (Equus caballus, sometimes seen as a subspecies of the Wild Horse, Equus ferus caballus) is a large odd-toed ungulate mammal, one of ten modern species of the genus Equus. ... Eye dominance (sometimes called eyedness) refers to the tendency to use one eye more than the other in certain tasks involving precise hand-eye coordination and a reasonably distant target. ... Binomial name Equus caballus Linnaeus, 1758 The horse (Equus caballus, sometimes seen as a subspecies of the Wild Horse, Equus ferus caballus) is a large odd-toed ungulate mammal, one of ten modern species of the genus Equus. ... Families Cacatuidae Psittacidae Parrots or Psittacines (pronounced [1],[2]) is an order (namely Psittaciformes) of birds that includes about 353 species. ... Mastodons or Mastodonts are members of the extinct genus Mammut of the order Proboscidea and form the family Mammutidae; they resembled, but were distinct from, the woolly mammoth which belongs to the family Elephantidae. ...

See also

• Ambidexterity and cross-dominance
• Dextrocardia
• Handedness
• Left-handed
• Ocular dominance
• Situs inversus
• List of famous left-handed people

Cross-dominance, also known as mixed-handedness, mixed dominance and cross laterality, is a motor skills manifestation in which a person not necessarily being truly ambidextrous favors one hand for some crucial and precise fine motor skill operations and the other hand for others tasks. ... Dextrocardia is a peculiar condition in which the heart is positioned on the right side of the chest while it is normally on the left (mirror-image). ... Handedness is an attribute of human beings defined by their unequal distribution of fine motor skill between the left and right hands. ... People who are left-handed are more dextrous with their left hand than with their right hand: they will probably also use their left hand for tasks such as personal care, cooking, and so on. ... It has been suggested that this article or section be merged into laterality. ... Situs inversus (also called situs transversus) is a rare congenital condition in which the major visceral organs are reversed or mirrored from their normal positions. ... This article or section does not cite its references or sources. ...

References

1. ^ Ellis, S. J., Ellis, P. J., Marshall, E., & Joses, S. (1998). Is forced dextrality an explanation for the fall in the prevalence of sinistrality with age? A study in northern England. Journal of Epidemiology and Community Health, 52, 41-44.
2. ^ C. Porac and S. Coren. Lateral preferences and human behavior. New York: Springer-Verlag, 1981.
3. ^ Theodore H. Blau, The torque test: A measurement of cerebral dominance. 1974, American Psychological Association.

External links

• Development and disorders of lateral dominance and the development of specialised centres and functions in the left and right brain hemispheres