高中生10點上學更好

In the UK, the clocks go back by one hour on Sunday to mark the end of British Summer Time. Experts have been weighing up a more permanent time shift in our daily schedules, particularly for tired teenagers who struggle with early school starts.

每年入冬時，英國把時鐘往後撥1個小時，這標誌着夏令時結束。專家們在考慮對我們的日常作息時間作出更為永久性的調整，特別是針對那些艱難應對大清早上學的沒睡醒的青少年。

The rethink on teen slumber is largely due to the emerging science on circadian rhythms. The genetics associated with body clocks earned this year's Nobel Prize for physiology or medicine. The timing of release of the sleep hormone melatonin is thought to change with age: during adolescence, secretion begins late at night and continues until about 8am. The sleep rhythm of a teenager can lag an adult by two to three hours.

重新思考青少年的睡眠問題，在很大程度上是因為新興的晝夜節律科學。與生物鐘有關的基因研究贏得了今年的諾貝爾生理學或醫學獎(Nobel Prize for physiology or medicine)。人體釋放睡眠荷爾蒙--褪黑激素的時間據信會隨着年齡改變：在青春期，褪黑激素在深夜開始釋放並持續到早上8點左右。青少年的睡眠節律可能比成年人晚兩到三個小時。

A report by the Rand Corporation argues that, for adolescents, delaying the start of school to 8.30am or later could bring a $140bn benefit to the US economy over 15 years. Some US school days start as early as 7am.

蘭德公司(Rand Corporation)的一份報告認為，把青少年的上學時間推遲到8點30分或更晚，有望在未來15年給美國經濟帶來1400億美元的效益。美國一些學校早上7點就開始上課了。

The gains, which amount to a dividend of $9.3bn a year, arise mainly from two predicted pay-offs: improved academic performance, which increases the likelihood of graduation and future work; and a reduction in car crashes, which means more students make it into the future labour supply.

這項收益--相當於每年93億美元--主要來自兩個預計回報：一是學習成績提高，從而增加畢業和未來就業的可能性;二是車禍事故減少，這意味着會有更多學生安好地加入未來的勞動力隊伍。

Marco Hafner, a Rand economist, says the gains could be even higher because the calculation of benefits were on the conservative side. The input to the macroeconomic simulation did not factor in other phenomena, such as the risks of suicide and obesity that are believed to be exacerbated by sleep deprivation.

蘭德的經濟學家馬爾科?哈夫納(Marco Hafner)表示，因為計算效益時偏向保守，所以實際效益可能更高。宏觀經濟模擬的輸入沒有考慮其他現象，比如自殺和肥胖風險--據信睡眠不足會加劇這類風險。

Rand, which used data from 47 US states, concluded that teenage sleep deprivation should be regarded as an economic problem with a possible solution. The financial rewards, it says, would quickly outweigh any associated costs of fixing it, such as rescheduling bus routes or extending after-school clubs.

蘭德利用美國47個州的數據得出結論認為，青少年睡眠不足應該被視為一個可能解決的經濟問題。該公司表示，經濟回報將很快超過解決該問題的相關成本，比如重新安排公交車時間表，或延長課外興趣小組的時間。

There have been concerns about "insufficient sleep" among adolescents - the recommendation is between eight and 10 hours per night - for some time in the US.

在美國，各方擔憂青少年"睡眠不足"--建議每晚睡眠8-10個小時--已經有一段時間了。

In 2014, the American Academy of Paediatrics published a policy statement recognising "insufficient sleep in adolescents as an important public health issue that significantly affects the health and safety, as well as the academic success, of our nation's middle and high school students".

2014年，美國兒科學會(American Academy of Pediatrics)發表政策聲明，承認"青少年睡眠不足是一個重要的公共衞生問題，對我國初中和高中學生的健康和安全、以及學習成績有顯著影響"。

Trials of delayed school start times have shown benefits such as increased sleep (children seem to go to bed at the same time but wake later), increased alertness, higher attendance and better mood. This led the academy to give its unequivocal backing for change.

推遲上學時間的試驗已經展現了一些好處，比如睡眠時間增加(孩子們似乎會在同樣的時間睡覺，但起牀時間更晚)、思維更加敏捷、出勤率提高以及情緒更好。這使得美國兒科學會明確支持這項改革。

Last month, however, a bill designed to enact such a change faltered in California. The bill, which has the backing of the Start School Later movement, a lobby group of parents, health professionals and policymakers, is likely to resurface in January. Many schools in other states have already acted.

然而，旨在落實這一改革的法案最近在加利福尼亞州不了了之。該法案得到了由家長、健康專家和政策制定者組成的遊説組織"晚點上學"(Start School Later)運動的支持，有可能2018年1月重新出爐。其他州的很多學校已經採取行動。

All the evidence points to teen sleeping patterns being a consequence of biology, not attitude, according to Kyla Wahlstrom, an educational policy specialist at the University of Minnesota, who has studied this issue since 1996.

明尼蘇達大學(University of Minnesota)的教育政策專家、從1996年開始研究該問題的凱拉?瓦爾斯特龍(Kyla Wahlstrom)表示，所有證據都表明青少年睡眠規律是生理學(而非態度)造成的。

Delayed start times, Dr Wahlstrom says, have immediate and noticeable impacts, such as a reduced rate of teenage car crashes. One county in Kentucky saw the number of teenage crashes fall by 16 per cent in the two years after school starts were delayed by an hour, a reduction attributed to the drivers being more alert. The crash rate rose by 8 per cent across the state as a whole.

瓦爾斯特龍博士表示，推遲上學時間可以帶來立即而明顯的影響，比如青少年車禍率降低。在把上學時間推遲一個小時後，肯塔基州某縣兩年期間的青少年車禍數量減少了16%，這被歸因於司機的精神更集中。同期肯塔基州全州的車禍增加了8%。

As well as the AAP, the American Medical Association and the Centers for Disease Control in the US, support such a change. About 250 US schools are thought to have redesigned their schedules to accommodate the recommendations.

與美國兒科學會一樣，美國醫學會(American Medical Association)和美國疾病控制預防中心(Centers for Disease Control)也支持這一改革。據信全美已有大約250所學校為落實相關建議而重新設計了課程表。

A similar debate has been stirring in the UK. In 2015, Paul Kelley, a professor at the Sleep and Circadian Neuroscience Institute at Oxford university, suggested that 16-year-olds should start no earlier than 10am. For 18-year-olds, an 11am start is preferable. Early starts, he says, mean pupils are usually performing suboptimally.

類似辯論也在英國升温。2015年，牛津大學(University of Oxford)睡眠和晝夜節律神經科學研究所(Sleep and Circadian Neuroscience Institute)教授保羅?凱利(Paul Kelley)建議，16歲學生的上學時間不應早於上午10點。對於18歲的學生，11點上學更好。他表示，過早上學通常意味着學生表現欠佳。

Not everyone concurs: scientists at the universities of Surrey and Harvard dispute that delayed starts will lead to teenagers getting more sleep. One unintended consequence, for example, might be students being exposed to artificial light for longer because of later bedtimes.

並非所有人都同意該結論：薩里大學(Surrey University)和哈佛大學(Harvard University)的科學家質疑推遲上學時間將導致青少年睡眠時間增加的結論。例如，一個意外後果可能是因為上牀睡覺時間推遲，學生們暴露在人造燈光下的時間更長。

Based on mathematical modelling, this contrary study suggested that turning down the lights in the evening would allow teenagers to get more sleep without the need for a change to the school day. The time that students spend on their mobile phones and other devices also crops up regularly as a complicating factor in teenage sleep studies.

這項相反的研究基於數學建模，它似乎表明，晚上早些關燈就可以讓青少年的睡眠時間增加，而無需改變上學時間。在青少年睡眠研究中，學生們花在手機及其他設備上的時間也經常會冒出來，成為一個使問題複雜化的因素。

Nevertheless, one London head of an independent school has chosen to push back the start of the day for sixth-formers to 9.30am. Explaining his decision in an article for the Times Educational Supplement, Jonathan Taylor pointed out that the 9-to-5 mode of working was disappearing anyhow. He criticised educators who clung to an early start out of "a misguided notion of traditional self-discipline?.?.?.?is it really more worthy to learn maths at 8.30am than 5pm?"

儘管如此，倫敦一傢俬立學校的校長選擇把高中生的上學時間推遲到早上9點30分。喬納森?泰勒(Jonathan Taylor)在為《泰晤士報教育增刊》(Times Educational Supplement)撰寫的文章中解釋了自己的決定，他指出，朝九晚五的工作模式反正將要終結。他指責那些堅持早上學的教育家是出於"自律這種具有誤導性的傳統理念……難道早上8點30分學數學，就一定比下午5點學數學更有價值嗎?"

Attendance and punctuality, Mr Taylor enthused, had improved - and the teenagers made for jollier company. Heaven knows, we could all do with happier teens.

泰勒興奮地表示，推遲上學時間後，學生的出勤率提高，遲到率下降，而且青少年們更容易相處了。天知道，我們都需要更快樂的青少年。