For many people, being left-handed means there are a lot of little, everyday inconveniences that you just learn to deal with; from scissors to desks, the world was designed for right-handed people. But there are some very weird things that go along with being left-handed, including a long history of suspicion and distrust, along with a scientifically proven tendency to develop a mental illness.
对许多人来说，成为一个左撇子意味着你必须学会克服日常生活中遇到的诸多不便，从使用剪刀到在桌上办公，这个世界无疑为右撇子量身定做的。不过在漫漫历史长河中，人们发现了许多关于左撇子的奇闻佚事，有一些科学研究甚至倾向于将惯用左手归因于某一类精神疾病。

10.People With Psychotic Disorders Are More Likely To Be Left-Handed
10.精神失常的人们更容易成为左撇子

Left-handed people have long been viewed with a certain amount of suspicion. Recently, science has shown that there might be a solid reason for that. In 2013, Yale University researcher Jadon Webb conducted a survey among patients diagnosed with different types of psychotic illnesses, including schizophrenia. Participants in the study were asked to fill out a questionnaire, which included the question about which hand they wrote with. The results were surprising. Researchers found that about 40 percent of those who were suffering from psychosis were left-handed. That's a significant percentage, considering that only about 10 percent of the population is left-handed.
长久以来，人们总是带着有色眼镜来审视左撇子，然而最近，科学家们证实，这一切也许是有理可依的。耶鲁大学的杰登·韦伯（Jadon Webb）教授在2013年对那些被诊断患有不同类型的精神疾病的人们做了个调查，其中包括精神分裂症患者。这些人被要求填写一份问卷，其中一个问题就是他们是否是左撇子。统计结果出人意料。研究者发现在这些存在精神问题的参与者中，40％是左撇子。考虑到全世界仅有10％的人惯用左手，40％无疑是个瞩目的数据。
Researchers believe that being left-handed involves having a sort of biomarker that might indicate a predilection toward mental illness—specifically psychosis. In studies done with other groups suffering from mental illness such as depression, there was no similar correlation. When these other groups were studied, there was a much more expected pattern where the number of left-handed sufferers was comparable to the overall percentage of left-handed people in the population.
研究者认为，左撇子也许存在某种生物标记，使得他们更容易患上精神疾病——尤其是精神错乱。因为另一项针对抑郁症患者的调查表明，其与左撇子并没有必然联系。并且在对其他患病人群的调查中，惯用左手的人口率基本在10％上下浮动，并没有类似精神病患者中出现的高几率。

9.Our Ancestors Also Had A Left-Handed Minority
9.我们的祖先中也有少部分左撇子

We tend to think of right- or left-handed dominance in terms of modern things, like what hand we write with or use for the television remote. But, it turns out, early humans were favoring one or the other even 500,000 years ago. Researchers have taken a look at Neanderthal tools and have found that the vast majority of them show wear and tear consistent with right-handed use. Many of the tools were used in the cleaning of hides, which the individual would typically grip with their teeth and rake with a tool to clean. Teeth would often get scratched by the stone tool, and the direction of the scratches indicates which hand was used. In most cases, it was the right hand. There were, of course, left-handed individuals. Today, about 10 percent of the population is left-handed, which seems to be fully consistent with the researchers' findings about Neanderthals. This supports the theory that they're much more like us than has been previously thought. Even other animals that are thought to be pretty close to us on the evolutionary tree—like gorillas and chimpanzees—are only about 5 percent more likely to favor their right hands than their left hands.
我们似乎总是认为惯用左右手之分是现代的事情，就像我们习惯于用哪只手来写字或是按电视机遥控板。但是事实上，早在50万年前，人们就有了左右手之分。一些学者研究了尼安德特人（neaderthal）的工具后发现，其中大多数工具上的磨损和裂纹都昭示着它们的使用者是右撇子。大部分工具是用来处理兽皮的。通常人们会抓住猎物的牙齿，然后用那些工具耙平兽皮。因此牙齿上会留有一些刮痕，研究者正是通过这些刮痕的方向来判断使用者惯用哪一只手——通常都并非左撇子。但是，当然也有一些惯用左手的人留下的方向不同的刮痕。现代大约10％的人们是左撇子，这和关于尼安德特人使用工具的调查结果高度一致。可见左撇子自古就存在，并不像我们所认为的是现代生活所独有的。即使是那些在进化史上和人类高度相似的物种——比如黑猩猩——也有大约5％更偏好使用右手。

8.Left-Handed Tendencies And Language
8.左撇子的成因及语言

No other animal has such a huge bias against being left-handed. So why humans? It's thought that it has something to do with language. For most people, language develops in the left side of the brain—specifically, in Broca's area. This is where we not only develop ideas but translate them into a form of communication that others can understand. Since the left side of the brain controls the right side of the body, the prevalence of right-handed individuals is an outward sign of left-brain dominance.
大多数动物并不像人类那样有左右手的概念，这是为什么呢？通常人们认为这和语言有关系。对于大部分人来说，语言由大脑左半区块的白洛嘉区（Broca's area）操控，它帮助我们表达心中想法，使得人与人之间得以交流。而由于大脑左叶操控右半身体，因此右撇子的动作流利度其实取决于左半脑的指挥。
However, it's now been discovered that, in some people, language skills happen in the right side of the brain. These individuals are subsequently left-handed. It's not just that cut-and-dried, either. The more a person favored one hand or the other, the stronger the connection was with the other side of the brain. People who use their left hand for almost everything have an extremely high chance of being right-brain language dominant. Additionally, those who have a familial history of a high rate of left-handed individuals also have a stronger right-brain language processing center, suggesting that as a species we became left-handed and right-handed when we started developing language.
然而，目前研究发现有些人的语言中枢在大脑右半球。这些人于是就成了左撇子。事情当然不是这么简单。一个人对惯用手越依赖，其肢干与另一边大脑的联系就越紧密。一个在生活中完完全全依赖于左手的人多半有右半叶语言中枢，那些有家族遗传因素的左撇子们也如是。这证明了语言的产生使得我们开始有左右手的区分。

7.Left-Handed Spiral Stairs
7.左旋阶梯

It's well known that many medieval castles have spiral staircases built as a defense measure. A spiral staircase that turns clockwise gives the defender (presumably the one backing up the stairs or coming down them) a better freedom of movement. The defender can place his left hand on the central "post" for balance and strike down with the sword in his right hand. That assumes the defenders are right-handed, which is a problem for those who aren't. So what's a left-handed lord to do?
众所周知，许多中世纪城堡中都建有螺旋楼梯来作为防御措施。通常，一个顺时针旋梯可以让护卫队（尤其是背对着退上台阶或者从楼上下来的士兵）的行动更自由。卫兵可以在右手持剑的同时用左手扶着楼梯中央的支撑柱以保持平衡。当然这是以假设护卫队成员都惯用右手持剑为前提的，那么那些左撇子君主公爵该怎么办呢？
Ferniehirst Castle in Scotland is the ancestral home of the Kerr family, which traces their family tree back to their arrival in Britain alongside William the Conqueror in 1066. They're said to have a long history of left-handedness running in the family. According to the story, many of the Kerr homes and castles—like Ferniehirst—were constructed with spiral staircases that go counterclockwise (as pictured above) instead of the traditional clockwise ones. This allowed the largely left-handed clan to maximize their defenses, making it easier for them to fight while simultaneously presenting a major challenge to anyone who tried to take their castles by force. The early lords discovered the massive advantage held by left-handed fighters, and it became tradition to train all their guards and soldiers to fight left-handed. This lead to the term "Kerr-handed" or "corrie-fisted" to describe someone who favors their left hand.
苏格兰的芬尼赫斯特城堡（ Ferniehirst Castle）是科尔（Kerr）家族祖传的居所。科尔家族的先祖随着威廉一世（William the Conqueror）在1066年来到英国。左撇子在这个家族的传承中由来已久。因此，科尔名下的房屋、城堡——比如芬尼赫斯特城堡——都采用了逆时针的左旋阶梯（如上图所示）而非传统的顺时针。大部分科尔宗族借此增强了他们的防御力，使得他们在战斗的同时更好地阻止入侵者。那些公爵们发现这些左撇子士兵在对战中占有很大的优势，因此他们开始特意训练他们的警卫和士兵们左手持剑。久而久之，左撇子就又被大家称为"科尔军队"（Kerr-handed）或者"苏格兰拳头"（corrie-fisted）。

6.Fear Of The Left-Handed Might Be Innate
6.人们潜意识对于"左"的恐惧

History hasn't been kind to the left-handed. They were made to retrain their hands and even punished for using the "wrong" one. But now, science is suggesting that it's not just the desire to make people conform to a certain standard that has created this bias against left-handed people. According to researchers at the University of Utah, things that have to do with our left side are innately more scary. For the experiment, researchers exposed their subjects to a number of different threats, coming from either their right or left side. For example, in one case, participants were told that an earthquake had hit to the left or to the right of their city (on a map shown) and asked whether they would evacuate because of the danger of aftershocks. The earthquake to their left was seen as much scarier, and more people chose to evacuate.
历史对于左撇子并不仁慈。许多左撇子都努力尝试训练自己的右手，甚至因为"错误"的用手而遭到批评指责。不过近来的研究表明，人们对左撇子的偏见并不是简单的因为大家希望遵从一套固定的行事标准。一项犹他州大学的调查显示，人们潜意识中对于"左"有一种恐惧感。在一个试验中，参与者被询问假如他们所生活的城市的左半边或者右半边（地图上的）发生了一场地震，他们是否会选择撤离城市以防余震的危害。结果表明，发生在城市左半边区域的地震在人们潜意识中要可怕得多，因此更多的人会选择撤离。
Similar results were found when the threat was changed to a radioactive disaster; even though the occurrence on the right was closer, the left was viewed as more of a threat. People were also more disgusted by objects on their left, as illustrated by how far out of their way they went to avoid things like fake poop. There are a couple of different theories about why this happens, such as our brain's tendency to overcompensate for things and favor the right, as well as most of us feeling more capable of defending ourselves from threats on our stronger—right—side.
相似的结果也出现在核辐射威胁中。即使右边发生的事件和他们关系更密切，人们依然更畏惧左边发生的事件。从被实验者遇见假动物粪的躲避距离可以看出，人们甚至会更讨厌他们左手边的事物。有一些理论可以解释这个现象，比如大脑的过度补偿机制以及对右边的偏爱，并且当威胁来自于右方时我们通常更能应对自如。

翻译：周予星 来源：前十网