《神经心理学》期刊发表的一篇最新研究发现，左撇子的人面临更多的心理健康问题，包括多动症、失读症，甚至精神分裂症。

New research published in the journal Neuropsychologia finds that left-handed people are at increased risk for certain mental health issues, including ADHD, dyslexia（难语症） and even schizophrenia（精神分裂症） .

For example, while left-handed people make up only 10 percent of the population, 20 percent of schizophrenics are left-handed. And those who are ambidextrous¹（双手灵巧的） (able to use both hands), only an estimated 1 percent of the total population, may be even more at risk; 30 percent of schizophrenics are ambidextrous.

However, the Wall Street Journal reports there is also good news for lefties of the world, (of which I am one):

On average there is no significant difference in IQ between righties and lefties, studies show, belying² popular perceptions. There is some evidence that lefties are better at divergent thinking（发散思维） , or starting from existing knowledge to develop new concepts, which is considered an element of creativity.

And whatever their political persuasion³, lefties are in good company: Six of the past 10 presidents, including both Barack Obama and George H.W. Bush, have been left-handed.

Still, left-handed people, perhaps owing to their greater artistic⁴ inclination⁵（倾向，爱好） , tend to earn about 10 percent less in annual salaries than their right-handed counterparts, according to a recent Harvard University study.

Doctors are still unable to determine what causes hand preference but are finding that environmental factors, particularly stress in the womb, may play a leading role:

Babies born to older mothers or at a lower birth weight are more likely to be lefties, for example. And mothers who were exposed to unusually high levels of stress during pregnancy⁶ are more likely to give birth to a left-handed child. A review of research, published in 2009 in the journal Neuropsychologia, estimated that about 25% of the variability in handedness is due to genetics.

People commonly say that left-handed people operate with the right side of their brain, while right-handed people use the left side. And to some extent, that's not only proving to be true, but may also explain why lefties are slightly more prone⁷ to psychological disorders⁸:

Some 70% of lefties rely on the left hemisphere for their language centers, a key brain function, says Metten Somers, a psychiatrist⁹ and researcher who studies brain lateralization at Utrecht University Medical Center in the Netherlands. This doesn't appear to present problems, scientists say. The other 30% of lefties appear to exhibit either a right-dominant or distributed pattern, Dr Somers says. They may be more prone to impaired¹⁰ learning or functioning, and at greater risk for brain disorders, he says.