你有多久沒睡「美容覺」了？瑞典一項研究顯示，「美容覺」的確有作用，睡得好確實能讓人看上去更有吸引力，睡不好則會讓你的形象減分。
2017年3月21日，陝西省渭南市智樂幼兒園的老師和小朋友們在做睡眠遊戲。新華社發（崔正博 攝）
Beauty sleep is a real thing, according to researchers who have shown that people who miss out on sleep do appear less attractive to others.
「美容覺」確有其事。研究人員表示，比起睡得好的人，睡眠不足的人顯得沒有那麼光彩照人。
A couple of bad nights is enough to make a person look "significantly" more ugly, their sleep experiments suggest.
研究人員開展的睡眠實驗結果顯示，幾個晚上睡得不好便足以讓一個人看起來「特別地」不好看。
Dark-circled "panda" eyes and puffy lids can even put others off socialising with you, they say.
研究人員稱，黑眼圈和腫腫的眼皮甚至可能會讓身邊的人遠離你。
People were rated by strangers as less healthy and approachable when they had tired faces.
當人們表現出疲憊相時，素不相識的人會認為他們的身體狀況不佳且不是很好接近。
The researchers asked 25 university students, some male and some female, to be the guinea pigs in their sleep experiment.
研究人員請25名大學生參與了睡眠實驗，其中有男有女。
The volunteers - who were given payment for their help - were sent home with a kit that would measure their night-time movements to check that they had not cheated and slept when they should not have.
志願者在參與實驗後可以得到一定的報酬。研究人員向他們各自發放了一套工具，讓他們帶回家。這套工具會通過測量他們夜間的活動，以驗證他們沒有說謊，在原本不會睡覺的時候進入睡眠狀態。
They were asked to get a good night's sleep for two consecutive nights.
志願者被要求連續兩個晚上保持良好的睡眠狀態。
A week later, they were asked to restrict themselves to only four hours sleep per night for two nights in a row.
一個星期後，他們被要求將他們的睡眠時間壓縮到連續兩天每天僅睡四個小時。
The researchers took make-up free photos of the volunteers after both the good and the bad sleep sessions.
在志願者進行了好的睡眠和差的睡眠之後，研究人員分別拍攝了志願者們的素顏照片。
Next, they asked 122 strangers - women and men living in Sweden's capital city, Stockholm - to have a look at the photos and rate them on attractiveness, health, sleepiness and trustworthiness, as well as asking them: "How much would you like to socialise with this person in the picture?"
接著，研究人員召集了122名與志願者素不相識的陌生人。他們當中有男有女，都住在瑞典首都斯德哥爾摩。這些人被要求看著志願者的照片，對他們的魅力程度、健康狀況、睡眠情況和信任程度進行評價。研究人員還會問他們一個問題：「你有多想跟照片上的這個人交朋友？」
The strangers were good at judging if the person they were looking at was tired, and, if they were sleepy, their attractiveness score suffered.
這群人的眼力很好。如果照片上的人顯得疲倦不堪，或者看起來很缺覺，他們魅力程度的分數便很低。
The strangers also said they would be less willing to socialise with the tired students, who they also perceived to be less healthy, Royal Society Open Science journal reports.
據英國期刊《皇家協會開放科學》報導，這些陌生人也表示，他們更不願意與那些看起來很累的學生交朋友，他們認為這些人的身體狀況不太好。
The Karolinska Institute researchers says this makes sense in evolutionary terms.
來自卡羅林斯卡學院的研究人員說，從進化的角度來看，這十分符合常理。
"An unhealthy-looking face, whether due to sleep deprivation or otherwise, might activate disease-avoiding mechanisms in others."
「一張看起來不健康的臉，不管它是由於睡眠不足還是其他原因導致的，都可能會激活其他人身體內躲避疾病的機制。」
In other words, people don't want to hang around with people who might be ill, whereas someone who looks energetic and fit will hold lots of appeal.
換句話說，人們不想跟可能患病的人待在一起。而那些看起來活力四射、身體健康的人則魅力十足。
Lead researcher Dr Tina Sundelin added: "I don't want to worry people or make them lose sleep over these findings though.
首席研究員蒂娜•孫德琳博士補充道：「我不希望這些實驗結果讓人們擔憂或者睡得不好。」
"Most people can cope just fine if they miss out on a bit of sleep now and again."
「偶爾睡得不好沒有關係，大部分人都可以恢復得很好。」
Dr Gayle Brewer, a psychology expert at the University of Liverpool and member of the British Psychological Association, said: "Judgement of attractiveness is often unconscious, but we all do it, and we are able to pick up on even small cues like whether someone looks tired or unhealthy.
蓋利•布魯爾博士是利物浦大學的一名心理學專家及英國心理學協會成員。他說：「對外表魅力程度的評價往往是無意識的，但是我們一直都在做這件事。我們能夠從一些很小的細節，比如說這個人是否疲憊或者是否健康，來對他人進行評價。」
"We want our partners to be attractive and energetic.
「我們希望我們的伴侶看起來魅力十足，充滿活力。」
"This study is a good reminder of how important sleep is to us."
「這個研究對我們來說是一個很好的提醒，它告訴我們，睡眠是多麼重要。」