關於左撇子的十大奇談(上)

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.

對許多人來說，成爲一個左撇子意味着你必須學會克服日常生活中遇到的諸多不便，從使用剪刀到在桌上辦公，這個世界無疑爲右撇子量身定做的。不過在漫漫歷史長河中，人們發現了許多關於左撇子的奇聞佚事，有一些科學研究甚至傾向於將慣用左手歸因於某一類精神疾病。

le With Psychotic Disorders Are More Likely To Be Left-Handed

10.精神失常的人們更容易成爲左撇子

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.

長久以來，人們總是帶着有色眼鏡來審視左撇子，然而最近，科學家們證實，這一切也許是有理可依的。耶魯大學的傑登·韋伯（Jadon Webb）教授在2013年對那些被診斷患有不同類型的精神疾病的人們做了個調查，其中包括精神分裂症患者。這些人被要求填寫一份問卷，其中一個問題就是他們是否是左撇子。統計結果出人意料。研究者發現在這些存在精神問題的參與者中，40％是左撇子。考慮到全世界僅有10％的人慣用左手，40％無疑是個矚目的數據。

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.

研究者認爲，左撇子也許存在某種生物標記，使得他們更容易患上精神疾病——尤其是精神錯亂。因爲另一項針對抑鬱症患者的調查表明，其與左撇子並沒有必然聯繫。並且在對其他患病人羣的調查中，慣用左手的人口率基本在10％上下浮動，並沒有類似精神病患者中出現的高几率。

Ancestors Also Had A Left-Handed Minority

9.我們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.

我們似乎總是認爲慣用左右手之分是現代的事情，就像我們習慣於用哪隻手來寫字或是按電視機遙控板。但是事實上，早在50萬年前，人們就有了左右手之分。一些學者研究了尼安德特人（neaderthal）的工具後發現，其中大多數工具上的磨損和裂紋都昭示着它們的使用者是右撇子。大部分工具是用來處理獸皮的。通常人們會抓住獵物的牙齒，然後用那些工具耙平獸皮。因此牙齒上會留有一些刮痕，研究者正是通過這些刮痕的方向來判斷使用者慣用哪一隻手——通常都並非左撇子。但是，當然也有一些慣用左手的人留下的方向不同的刮痕。現代大約10％的人們是左撇子，這和關於尼安德特人使用工具的調查結果高度一致。可見左撇子自古就存在，並不像我們所認爲的是現代生活所獨有的。即使是那些在進化史上和人類高度相似的物種——比如黑猩猩——也有大約5％更偏好使用右手。

-Handed Tendencies And Language

8.左撇子的成因及語言

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.

大多數動物並不像人類那樣有左右手的概念，這是爲什麼呢？通常人們認爲這和語言有關係。對於大部分人來說，語言由大腦左半區塊的白洛嘉區（Broca's area）操控，它幫助我們表達心中想法，使得人與人之間得以交流。而由於大腦左葉操控右半身體，因此右撇子的動作流利度其實取決於左半腦的指揮。

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，目前研究發現有些人的語言中樞在大腦右半球。這些人於是就成了左撇子。事情當然不是這麼簡單。一個人對慣用手越依賴，其肢干與另一邊大腦的聯繫就越緊密。一個在生活中完完全全依賴於左手的人多半有右半葉語言中樞，那些有家族遺傳因素的左撇子們也如是。這證明了語言的產生使得我們開始有左右手的區分。

-Handed Spiral Stairs

7.左旋階梯

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?

衆所周知，許多中世紀城堡中都建有螺旋樓梯來作爲防禦措施。通常，一個順時針旋梯可以讓護衛隊（尤其是背對着退上臺階或者從樓上下來的士兵）的行動更自由。衛兵可以在右手持劍的同時用左手扶着樓梯中央的支撐柱以保持平衡。當然這是以假設護衛隊成員都慣用右手持劍爲前提的，那麼那些左撇子君主公爵該怎麼辦呢？

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.

蘇格蘭的芬尼赫斯特城堡（ Ferniehirst Castle）是科爾（Kerr）家族祖傳的居所。科爾家族的先祖隨着威廉一世（William the Conqueror）在1066年來到英國。左撇子在這個家族的傳承中由來已久。因此，科爾名下的房屋、城堡——比如芬尼赫斯特城堡——都採用了逆時針的左旋階梯（如上圖所示）而非傳統的順時針。大部分科爾宗族藉此增強了他們的防禦力，使得他們在戰鬥的同時更好地阻止入侵者。那些公爵們發現這些左撇子士兵在對戰中佔有很大的優勢，因此他們開始特意訓練他們的警衛和士兵們左手持劍。久而久之，左撇子就又被大家稱爲"科爾軍隊"（Kerr-handed）或者"蘇格蘭拳頭"（corrie-fisted）。

Of The Left-Handed Might Be Innate

6.人們潛意識對於"左"的恐懼

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.

歷史對於左撇子並不仁慈。許多左撇子都努力嘗試訓練自己的右手，甚至因爲"錯誤"的用手而遭到批評指責。不過近來的研究表明，人們對左撇子的偏見並不是簡單的因爲大家希望遵從一套固定的行事標準。一項猶他州大學的調查顯示，人們潛意識中對於"左"有一種恐懼感。在一個試驗中，參與者被詢問假如他們所生活的城市的左半邊或者右半邊（地圖上的）發生了一場地震，他們是否會選擇撤離城市以防餘震的危害。結果表明，發生在城市左半邊區域的地震在人們潛意識中要可怕得多，因此更多的人會選擇撤離。

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.

相似的結果也出現在覈輻射威脅中。即使右邊發生的事件和他們關係更密切，人們依然更畏懼左邊發生的事件。從被實驗者遇見假動物糞的躲避距離可以看出，人們甚至會更討厭他們左手邊的事物。有一些理論可以解釋這個現象，比如大腦的過度補償機制以及對右邊的偏愛，並且當威脅來自於右方時我們通常更能應對自如。

翻譯：周予星 來源：前十網