If so, one in ten people around the world is like you.

如果是，世界上每十個人就有一個人像你一樣。

However, nine out of ten people are right-handed.

但反之，十個人裡有九個人是右撇子。

[1. Human handedness starts in the stone age.]

[1. 自石器時代起，人們開始有慣用手。]

Stone tools suggest that most of our ancestors were, like most of us, right-handed.

石器工具也證明了我們大部分的祖先，像我們一樣是右撇子。

It's hard to pin down when left-handedness started, but we do have evidence that there were left-handed Neanderthals 500,000 years ago.

很難確切地講出左撇子是從什麼時候開始出現的，但我們有證據證明 500000 年前的尼安德特人也有左撇子。

How do we know this?

我們怎麼知道這些的？

Well, they were probably eating raw meat, which is tough old stuff.

因為他們可能是吃生肉，這種不怎麼好吃的古早味。

Archaeologists think the Neanderthals would sink their teeth in, and then use a sharp piece of stone to cut the meat near their mouth.

考古學家認為尼安德特人會將牙齒卡在食物上，並用一片鋒利的石頭將靠近嘴巴的肉切掉。

Sometimes the stone slipped.

有些時候石頭不小心滑掉。

And from the direction of the scratches, 10 percent of Neanderthals seem to have held the cutter in their left hand.

而根據嘴上的刮痕，有 10% 的尼安德特人會將切割的石片握於左手。

[2. Left handers, your brains are more bespoke.]

[2. 左撇子們，你們的大腦比較像是為你們量身打造的。]

For right-handers, it's normally the left side of the brain that's associated with speech and language.

就右撇子而言，左腦通常是與言談和語言能力有關。

What though if you are left-handed?

但如果你是左撇子呢？

Despite using their left hand for writing, two thirds of left-handers are just like right-handers, in having language in their left brain.

就算是使用左手書寫，有三分之二左撇子的大腦仍像右撇子一樣，語言區位於左腦。

But, a third of left-handers have language in the right side of their brain—the opposite of right-handers.

但是，有三分之一左撇子的語言區在右腦，與右撇子的人相反。

Left-handers are much more variable in the ways their brains are organized.

左撇子的腦部規劃會有比較多變化。

In contrast, right-hander's brains are off the peg.

相較之下，右撇子的腦子就都是均規的。

Left-handedness is therefore much more of a mixture of strengths and weaknesses, pros and cons coming from having a somewhat differently organized brain.

左手為慣用手，因為大腦規劃比較不一樣而好壞參半。

Is your baby sucking its thumb?

你的寶寶喜歡吃手指嗎？

Psychologist Peter Hepper in Belfast studied several hundred scans where the baby in the womb was seen sucking its thumb.

一位來自貝爾法斯特的心理學家 Peter Hepper 研究了好幾百份超音波片，看到還在子宮中的寶寶們吸手指。

About 90 percent of babies sucked their right thumb.

有約 9 成的寶寶是吸他們的右大拇指。

And at 12 years old, almost all of those right thumb suckers were right-handed.

而在 12 歲時，幾乎所有吸右手大拇指的人都是右撇子。

Whereas three quarters of the left thumb suckers would become left-handed.

而四分之三吸左手拇指的人會成為左撇子。

Genes are clearly also important.

基因也明顯地很重要。

One left-handed parent, and you're more likely to be left-handed yourself.

有一位左撇子的家長，你很有可能會是左撇子。

Both parents left-handed, and you're even more likely.

如果父母兩位都是左撇子，你就更有可能是了。

About a one-in-four chance.

約四位中有一位會是左撇子。

Infants often go through a random chaotic phase where they use the right hand one day, and the left the other, perplexing their parents.

嬰兒通常會經歷一段很混亂的時期，他們會一下用右手一下用左手，讓他們的家長很困惑。

By about two years old, their handedness is usually consistent.

大約到兩歲時，他們的慣用手會固定下來。

[4. We could all be a little more ambidextrous if we tried.]

[4. 只要我們努力看看，都可以變得更加靈活。]

If you practise long and hard enough, then you can probably do anything equally well with either hand.

如果你夠努力練習，可能任何事都可以用兩隻手做。

Concert pianists are a good example, though it does take dedication.

音樂會鋼琴家就是一位很好的例子，雖然這真的需要付出努力。

In 1797, the right-handed Admiral Lord Nelson, had his right elbow shattered by a musket ball.

在 1797 年，一位右撇子的上將 Admiral Lord Nelson 右手肘被火槍子彈給擊碎。

The arm was amputated.

手臂被截肢。

Within six months though, Nelson had learnt to write fluently with his left hand.

在六個月內，Nelson 學會用左手熟練地寫字。

But the motivation was there, of course.

但這當然有動機啦！

Professional sports players are also motivated to practice, as it can give an added edge in competition.

專業的運動員也很願意練習這點，因為在比賽中可以提高競爭力。

Footballers train to kick well with either foot, and when practicing they use both feet confidently and well.

足球員訓練要兩隻腳都可以踢得了好球，在練習時他們也有自信地踢出了好球。

But under pressure, when the action's hot, they often revert to using their dominant foot.

但在有壓力，或動作比較挑戰時，他們通常會切換回自己的慣用腳。

Even if it means taking an extra half step before shooting for goal.

就算意味著在射門前要踏出額外的半步。

Reversing your natural sidedness does come with a cost.

切換慣用邊的確有代價。

You could be almost equally good with each hand or foot, but the price would be so much time practicing that you probably wouldn't do anything else with your life.

你可以兩邊手腳都一樣熟練，但代價是你會花很多時間練習，多到沒時間去做任何其他事情。

[5. Many of those famous left-handers were actually right-handed.]

[5. 許多有名的左撇子其實都是右撇子。]

The list of famous left-handers seems pretty impressive.

左撇子名人榜單上的人都很令人驚艷。

Albert Einstein, Beethoven, Bob Dylan, Picasso, Neil Armstrong, Winston Churchill, Benjamin Franklin, Marilyn Monroe, all are claimed—on the Internet—to be left-handed.

愛因斯坦、貝多芬、鮑伯・迪倫、畢卡索、阿姆斯壯、邱吉爾、富萊克林、瑪麗蓮夢露，所有人在網路上都說自己是左撇子。

And in each case, it's almost certainly wrong.

但就個情況而言，幾乎可以肯定是錯誤的。

The evidence of left-handedness is often very dodgy indeed.

要證明是左撇子的證據通常都很難確定。

For instance, there's a book with a painting of Beethoven writing with his left hand, the picture has clearly been flipped.

好比說，有一本書畫著貝多芬用著左手寫字，但這張圖很明顯是被翻轉過的。

There are many reasons why people may wrongly claim that famous individuals are left-handed.

或許有很多原因可以解釋為什麼人們會錯誤地聲稱名人都是左撇子。

Tribal loyalty and the reflected glory of feeling part of the same handedness club are just two of them.

族群認同感和使用相同慣用手群體的驕傲感是兩個原因。

Perhaps when it comes down to it, there is a little bit of the left-hander in each of us.

或許追根究柢，我們每個人都可以多少算是左撇子。