Right-handed

For a right-handed particle in physics, see Chirality (physics).

File:Handshake.jpg

Shaking with the right hand while delivering a certificate with the left.

One who is right-handed is more dexterous with one's right hand than with one's left hand: one will probably write with their right hand, and probably also use this hand for tasks such as personal care, cooking, and so on. According to different studies, 85% to 90% of the population is right-handed, while most of the remaining are left-handed. A small percentage of the population can use both hands equally well; a person with this ability is deemed to be ambidextrous.

Why is the population right-hand dominant?

There is no prevailing theory that explains why right-handedness is so much more prevalent than left-handedness.. Neurologically, the motor skills of the right side of the body are controlled by the left hemisphere of the brain, so researchers believe the explanation may ultimately be found in the differences between the two halves of the brain. For example, a recent study found that right-handers use the right side of the brain to focus on an entire image, but the left side of the brain to focus on details within an image.. This observed difference, like many others, shows the effects of right-handedness but does not clearly indicate its cause.

Left/right-footedness and ocular dominance

Being right-handed does not always mean that the favoured foot is also on the right side. When playing football for instance, many people prefer using their left foot rather than the right, despite being right-handed.

People typically also have a dominant eye, a preference known as ocular dominance. There is only a weak correlation between being right handed and left eyed.

Theories explaining right-hand dominance

Main article: Handedness

• Warrior and his shield theory: This theory attempts to explain right-handedness by the position of a warrior's shield and his heart. Basically, since the heart is slightly nearer to the left side of the body, a right-handed warrior (who holds his shield with his left hand to free the right hand for a weapon) would be better able to protect his heart and therefore more likely to survive.

• Brain hemisphere division of labor: The premise of this theory is that since both speaking and handiwork require fine motor skills, having one hemisphere of the brain do both would be more efficient than having it divided up.

Right-handedness in society

In the past, many schools around the world forced left-handed children to write right-handed. In Hinduism, the right hand must be used for all auspicious and respectful activity, including eating, giving, receiving, and worshipful offering. The left hand is used in times of inauspiciousness, as a sign of disrespect, and for wiping oneself after using the bathroom. In Islam as well, one is required to use the left hand for tasks such as wiping oneself after using the bathroom and the right hand for eating.

A good number of technological devices are made primarily for right-handers; examples of everyday objects primarily designed for right-handers include refrigerators, scissors, microwaves, can-openers, button-down shirts, computer mice, and padded kitchen mittens (padded on one side only). Left-handed golf clubs are more difficult to find than right-handed ones. Many classical-era Japanese swords were (and even modern cooking knives are) favored to cut more efficiently for the right-hander. Musical instruments such as guitars are also set up for right-handers. Military rifles designed to be shot only from the right shoulder have resulted in injuries from spent cartridge casings hitting left-handers in the eye and head.

See also

• Handedness
• Footedness
• Ocular dominance
• Orthodox stance in boxing