Left versus right: the impact of handedness on future earnings

For people who are left-handed, life presents unique and seemingly unfair challenges. Household items like scissors and manual can openers are difficult to manipulate, handshakes and high fives can be unexpected adventures, and spiral-bound notebooks and fountain pens are all but impossible to use. Worse yet, studies have long indicated that lefties have higher rates of alcoholism and shorter lifespans. The latest injustice: left-handed people earn less money than their right-handed counterparts.

In “The wages of sinistrality: handedness, brain structure, and human capital accumulation” (Journal of Economic Perspectives, Fall 2014), Harvard economist Joshua Goodman found that lefties earn 10 to 12 percent less each year than righties. The reason he offered is that lefties are generally born with a different brain structure that negatively affects their social and cognitive abilities. According to Goodman, this genetic difference inhibits social development, thus causing human capital deficits. As he indicates early in the paper, “Lefties have more emotional and behavioral problems, have more learning disabilities such as dyslexia, complete less schooling, and work in occupations requiring less cognitive skill.”

Goodman’s findings are based on his assessment of various studies from the United States and the United Kingdom. Using these data, he compares righties and lefties across a range of categories including cognitive skills; disabilities; and education, occupation, and earnings. With respect to earnings, he found that median income for lefties in the United States was $1,300 a year less than for righties.

One of the more interesting aspects of Goodman’s research is the role of maternity. The study finds that the negative outcomes generally present with lefties are absent among the left-handed children of left-handed mothers. Just as interesting, the right-handed children of left-handed mothers experience cognitive deficits at levels similar to lefties as a whole. This suggests that rather than some defect in brain structure unique to lefties, there may be an issue related to childrearing that is producing the negative outcomes found in the study.

Goodman’s research, if accepted, dispels the notion that lefties are disadvantaged because they are forced to navigate a world optimized for the majority—righties. But the idea that shortcomings amongst left-handers are generally related to faulty brain structure is likely to be received in an unwelcome manner by the left-handed community. However, the news isn’t all bad for lefties: studies have shown left-handed people to be overrepresented among the highly intelligent and highly creative; left-handedness provides an advantage in a host of athletic contests, including baseball, boxing, fencing, and tennis; and four of the last seven U.S. presidents have been lefties.