One does not choose to be born left-handed, to have to write in a world adapted to right-handed people, and in some cases for kids, even singled out in class…. What's more is that one Harvard researcher found that left-handed people have salaries 10 to 12% lower than those of right-handed people.
(http://pubs.aeaweb.org/doi/pdfplus/10.1257/jep.28.4.193 – Study carried out within a group of the same age bracket in USA, and in the UK.)
Fortunately, it is not a question of voluntary discrimination on the part of the employers, but the fact remains that left-handed people simply have a lower salary. A combination of factors makes their education more labour intensive, which could explain a lower level of education than that of right-handed people, a lesser proneness to getting jobs, and therefore a lower average salary (within a sample):
- Genetics can be the first to bear blame for left-handed people, and especially their mothers, if they are right-handed: they would have been even further affected during childhood with learning problems caused by lateralization with a right-handed mom.
- Then, the less adapted (if not hostile) environment would have also impeded their education.
- Lastly, they would naturally show more emotional disturbances.
As a bit of consolation for left-handed people, they are nevertheless proudly represented by some of the great names in sport (McEnroe and Nadal in tennis, for example) and 5 of the last 7 presidents of the United States were left-handed.
Useful and useless facts about left-handed people: