Discrimination against left-handedness

In a world dominated by right-handedness (preferential and predominant use of the right hand) left-handed people are discriminated against. Traditionally, humanity has looked upon left-handedness as a defect; since Roman times the left has been "sinister". This discrimination may be as overt as mocking left-handers and forcing them to switch to the use of their right hand, or covert, such as the lack of proper equipment (from scissors to baseball gloves to industrial machines) for left-handed use. Many countries in the east look on the left hand as unclean and discourage its use in society. Parents often go out of their way to discourage their children from predominant left-handed usage. Reproaching children for their left-handedness may lead to emotional problems, nervousness, and a poor self-image. Certain terms stigmatize, are offensive to, or discriminate against people who are left-handed (eg gauche, righteous).

Symbolic differentiations of left and right are virtually universal cultural classifications among humankind. Left handers live with a biased vocabulary "Adroit" and "Dextrous" are associated with the right hand, but "sinister" and "gauche" with the left. The righteous sit on the right hand of God. In 1909, French sociologist Robert Hertz made the following observation: "To the right hand go honours, flattering designation, prerogatives; it acts, orders, and takes. The left hand, on the contrary, is despised and reduced to the role of a humble auxiliary; by itself it can do nothing; it helps, it supports, it holds".

Recently, asymmetrical behaviour has been discovered in many living animal species, and palaeontologists have also found hints of preferentially "handed" behaviour in long extinct animals, such as trilobites -- sea creatures that evolved before animals first colonized the land (and long before the evolution of the hand) who persistently turned toward their favoured sides when attacking prey or evading predators.