Left-handed
Overview
Left-handedness is the preference for the left hand
over the right for everyday activities such as writing
. In ancient times it was seen as a sign of the devil, and was abhorred in many cultures. A variety of studies suggest that 10% of the world population is left-handed.
Left hand
Left hand may refer to any of:*Left-handedness, a term referring to a person who primarily uses their left hand to accomplish things*Left Hand , a comic book character owned by Marvel Comics...
over the right for everyday activities such as writing
Penmanship
Penmanship is the technique of writing with the hand using a writing instrument. The various generic and formal historical styles of writing are called hands, whilst an individual personal style of penmanship is referred to as handwriting....
. In ancient times it was seen as a sign of the devil, and was abhorred in many cultures. A variety of studies suggest that 10% of the world population is left-handed.
- Hand orientation is developed in fetuses, most commonly determined by observing which hand is predominantly held close to the mouth.
- In 2007, researchers discovered that specific alleles of at least one of three single-nucleotide polymorphisms upstream of the already known LRRTM1LRRTM1Leucine-rich repeat transmembrane neuronal protein 1 is a protein that in humans is encoded by the LRRTM1 gene.LRRTM1 is the first gene linked to increased odds of being left-handed, at least if inherited from the father's side...
gene were linked to left-handedness. - Twins theory: this theory postulates that left-handed individuals were originally part of an identical twin pair, with the right-handed twin fetus failing to develop early in development.
