車站的藍(lán)燈真的能防止自殺嗎?

In 2013, a scientific paper was published that would become the seed for thousands of viral news stories and social media posts. The suggestion was astounding: blue lamps at train stations prevented suicides at those locations. And scientists could even show that the suicides fell by as much as 84%.

2013年，一篇科學(xué)論文引發(fā)了數(shù)千篇連環(huán)新聞報道和社交媒體的討論。論文的結(jié)論令人吃驚：火車站的藍(lán)色燈光能減少自殺人數(shù)?？茖W(xué)家甚至計算出裝有藍(lán)光的車站自殺率下降了84%。

The idea has since caught on, inspiring similar projects in many other countries. But as with many interesting but complex science stories, some of the details have got a little distorted as it was passed along the way.

隨后，這個觀點流行起來，許多國家紛紛效仿。然而，跟許多有趣但復(fù)雜的科學(xué)故事一樣，這篇論文中的一些細(xì)節(jié)在傳播過程中被歪曲了。

It all started in the late 2000s, when a number of Japanese railway companies began installing blue lamps above train station platforms. It was an attempt to deter people from suicide in such places – a so-called “nudge” technique. Nudge techniques are ways of influencing behaviour that, although apparently subtle, can have surprisingly large impacts.

這要從2000年代初期說起，當(dāng)時，一些日本鐵路公司為了阻止臥軌自殺，開始在站臺上方安裝藍(lán)燈。這是一種所謂的“助推”技術(shù)，旨在通過一些因素在不知不覺中影響人們的行為，雖然看起來微不足道，但效果驚人。

The idea was that blue light can have an effect on people’s state of mind. One study in 2017 backed up this notion; it showed that people who had experienced psychological stress returned more quickly to a state of relaxation when they lay in a room bathed in blue light.

藍(lán)光可以影響人們的精神狀態(tài)。2017年的一項研究支持了這一觀點。研究表明，有心理壓力的人躺在灑滿藍(lán)光的房間里，能更快地恢復(fù)到放松的狀態(tài)。

Michiko Ueda at Waseda University heard about the railway companies’ experiments on station platforms and was told the lamps had proved to be a success. Ueda has studied a huge range of factors that may be influencing Japan’s suicide rate – from economics to natural disasters and even discussion of celebrity suicides on Twitter. But she says her first reaction to the railway companies’ claims was scepticism. “I thought we should follow up and I decided to contact the railway company to ask if they could provide data,” she explains.

早稻田大學(xué)(Waseda University)的上田美智子(Michiko Ueda)聽說了鐵路公司在站臺上的試驗，并得知藍(lán)燈確實成功降低了自殺率。她曾研究了一系列可能影響日本自殺率的因素，比如經(jīng)濟因素、自然災(zāi)害，甚至是推特上有關(guān)名人自殺的討論。她對于鐵路公司說法的第一反應(yīng)是懷疑。她解釋道：“我覺得應(yīng)該跟進這個實驗，就聯(lián)系了鐵路公司，問他們能否提供數(shù)據(jù)。”

After analysing 10 years’ worth of data on suicides at 71 Japanese train stations, Ueda and her colleagues found that there was some evidence of an effect on passengers. They saw an 84% reduction, a figure that was soon widely reported.

上田和她的同事分析了日本71個火車站10年來的自殺數(shù)據(jù)，發(fā)現(xiàn)有證據(jù)表明藍(lán)燈確實能對乘客產(chǎn)生影響，自殺率下降了84%，就是很快就被廣泛報道的那個數(shù)據(jù)。

Unfortunately, that’s not the whole story. When news reports about the findings came out, Masao Ichikawa at the University of Tsukuba took another look at the data. He pointed out that it was important to distinguish between data collected during the day and night at outdoor train stations. During the day, the lights may be easily missed, or even turned off.

遺憾的是，真相并非僅僅如此。當(dāng)此現(xiàn)象被報道后，筑波大學(xué)(University of Tsukuba)的市川雅雄(Masao Ichikawa)從另一角度對數(shù)據(jù)進行了研究。他指出，區(qū)分白天和晚上在室外火車站收集的數(shù)據(jù)很關(guān)鍵。白天，燈容易被忽視，甚至被關(guān)掉。

Ichikawa also scrutinised a measure known as the “confidence interval”. Statistical analyses always carry an inherent uncertainty around a particular result – such as the size of this effect – and the confidence interval expresses the possible range of those values. Ichikawa noticed that the confidence in in Ueda’s paper was extremely wide: 14-97%. “Statistically very unstable,” he says. This means the actual effect could have been as low as a 14% reduction – still a significant change, but not nearly as big as the media coverage had suggested.

市川還仔細(xì)研究了一個被稱為“置信區(qū)間”的指標(biāo)。統(tǒng)計分析得出的結(jié)果總是會有一些誤差，比如影響的大小，置信區(qū)間表示誤差值的可能范圍。市川注意到，上田研究中的置信區(qū)間十分大，從14%至97%。“這表明統(tǒng)計結(jié)果非常不穩(wěn)定，”他說。這意味著實際效果可能會低至14%，仍然顯著，但沒有媒體報道的那么夸張。

He hoped his own paper, published in response the following year, would ensure that people didn’t begin thinking that blue lights were a miracle deterrent – that they somehow had an extraordinary effect on people who were considering suicide.

他希望，自己下一年發(fā)表的回應(yīng)論文能夠降低人們對藍(lán)色燈光有神奇干涉效果的盲信，雖然它們在某種程度上對那些試圖自殺的人產(chǎn)生了巨大的影響。

The installation of protective barriers and screen doors along the edges of platforms could be far more useful, says Ichikawa. However, he acknowledges that they cost a lot more than blue lights. The expense may be worth it, though, if the blue light effect turns out to be minimal.

市川說，在站臺邊緣安裝防護欄和幕門可能會有用得多。然而，他也承認(rèn)安裝這些裝置成本遠(yuǎn)比藍(lán)燈高。但如果證明了藍(lán)光效果有限，多花些錢就是值得的。

Since publishing her paper, Ueda has been stunned by the number of enquiries she gets from railway firms around the world, including Switzerland, Belgium and the UK. “It’s amazing,” she says. There are already at least two examples of blue light installations in Britain – one at a train crossing in Scotland, and there are also such lights at Gatwick airport train station.

論文發(fā)表以來，上田收到了世界各地鐵路公司的詢問，包括瑞士、比利時和英國，數(shù)量之多讓她震驚。“太神奇了，”她說。英國已經(jīng)在至少兩處安裝了藍(lán)光裝置——蘇格蘭的一個鐵路行人橋和蓋特威克(Gatwick)機場火車站。

But Ueda is no proponent of the schemes. “Whenever somebody asks me whether they should do blue lights or platform screen doors, I will immediately answer, ‘You should do platform screen doors’,” she says.

上田本人并不支持藍(lán)燈。她說：“每次有人問我應(yīng)該裝藍(lán)燈還是站臺幕門，我都會毫不猶豫地回答，‘應(yīng)該裝幕門’。”

While she understands the issue of cost associated with the screen doors, she reiterates that it’s important to understand that the blue light effect may be more subtle than some think – and we still don’t know exactly what impact the lights are having.

雖然她也知道幕門成本高，但她重申，藍(lán)燈的影響可能比人們想象的要小得多。我們現(xiàn)在仍然不清楚燈光到底對人們產(chǎn)生了什么樣的影響。

For example, perhaps the installation of new, bright lights – regardless of colour – caused people to become more self-aware, thus changing their behaviour, suggests Ueda. And maybe after time the blue lights, should they be effective at preventing suicide, will fail because people will grow accustomed to them.

上田說：“也許只要安裝嶄新明亮的燈，不管顏色如何，都會增強人們的自我意識，從而改變他們的行為?？赡苓^段時間，這些能防止自殺的藍(lán)燈就會失效，因為人們漸漸習(xí)慣了它們的存在。”

Ueda is now conducting a fresh study to measure the psychological impact of blue lights, but there are already conflicting results on that point from other teams. The 2017 paper mentioned above gave credence to the idea that blue lights could be calming, but Stephen Westland, an expert in colour and design at the University of Leeds, says the lights may not influence another important factor – someone’s impulsiveness.

上田目前正在進行一項新的研究，旨在測量藍(lán)光對人們心理的影響。但其他團隊已經(jīng)在這一領(lǐng)域得出了與之矛盾的結(jié)果。前文提到的那篇2017年的論文證實了藍(lán)色燈光可以使人平靜，但是利茲大學(xué)(University of Leeds)色彩與設(shè)計專家韋斯特蘭(Stephen Westland)說，燈光可能無法影響另一種重要情緒——沖動。