We can explained it by their lower ability to lear and problem solve.
Sartarelli recruited 432 people, eight percent left-handers, to play a game. They had to put in effort and cut good deals. Some participants offered employment contracts to other participants. They played the roles of the “workforce” in the simulation.
The lefties achieved the same scores as the right-handers. They also brought home as much bacon in the simulation.
Researchers found some interesting relationships between the personality of left-handers and their performance.. They earned more when more extraverted, and less when more neurotic. At the same time, a 10 times bigger group of righties didn’t show this linking.
They also found that left-handers were more agreeable. Researchers connect these findings with lower salaries.
Sartarelli M (2016) Handedness, Earnings, Ability and Personality. Evidence from the Lab. PLoS ONE 11(10): e0164412. doi:10.1371/journal.pone.0164412