Life holds many frustrations¹ for left-handed people – from the everyday items designed for right-handers to folklore² saying they are in league with the devil.

对于左撇子来说，生活中有许多令人懊恼的事情，日常物件多是为右撇子设计的，民间传说还说他们是魔鬼的同伙。

So perhaps it is the result of dealing³ with such adversity（逆境，不幸） that, according to researchers, they are angrier than the average person.

Researchers found that among lefties, the two hemispheres of the brain communicate more with each other so have more interaction with the parts which produce negative emotions.

Everything from can openers to garden tools to knives and scissors tends to be designed without taking them into consideration.

Many generations of left-handed schoolchildren were forced to write with their right hand. They have endured centuries of stigma⁴（柱头，耻辱） that says being left-handed is evil or bad luck.

And they are often associated with clumsiness（笨拙，粗陋） and awkwardness.

The study, led by Ruth Propper, a psychology⁵ professor at Merrimack College in Massachusetts, found that the halves of the brain in those who are lefties or ambidextrous⁶（双手灵巧的） are more interlinked.

This makes them more moody⁷, research published in the Journal of Nervous and Mental Disease found.

Previous studies have shown that 'lefties' are more prone⁸ to negative emotions.

Many of the world's leaders and stars are left-handed, with some known for being hot-tempered.

One famously grumpy 'leftie' is Bob Geldof, who achieved fame thanks in part to swearing during TV coverage⁹ of Live Aid.

Another is tennis legend John McEnroe, who is as famous for his tantrums（发脾气，发怒） as his successes.

Current world leaders who are left-handed include Barack Obama and David Cameron.

But Lauren Milsom, owner of Anythinglefthanded.com, which sells goods for left-handed people, said: 'Left-handed people just get on with it and do not complain that much.

'We just deal with a world designed for right-handers.'