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Science and Technolgy.
科技。
Social status and health.
社會地位與健康。
Misery index.
貧困指數。
Low social status is bad for your health. Biologists are starting to understand why.
社會地位低對身體不好，生物學家開始理解此中的奧秘。
ONCE upon a time the overstressed executive bellowing orders into a telephone, cancelling meetings, staying late at the office and dying of a heart attack was a stereotype of modernity. That was before the Whitehall studies, a series of investigations of British civil servants begun in the 1960s. These studies found that the truth is precisely the opposite. Those at the top of the pecking order actually have the least stressful and most healthy lives. Cardiac arrest-and, indeed, early death from any cause-is the prerogative of underlings.
曾今，人們對現代化的一個根深蒂固的印象是，領導們在巨大壓力的折磨之下，對著電話狂吼，下達命令，取消會議，待在辦公室到很晚，最后死于心臟病。可是，自1960年代開始的英國白廳對英國政治家們展開的一系列調查之后，這種印象開始改變，因為調查發現事實卻完全不是那么回事。實際上處于社會高層的人們承受的壓力最小，生活最健康。心跳驟停——而且，確實是，不管是出于什么原因的早死——那都是做下屬的才有的事。
Such results have since been confirmed many times, both in human societies and in other primate species with strong social hierarchies. But whereas the pattern is well-understood, the biological mechanisms underlying it are not. A study just published in the Proceedings of the National Academy of Sciences, however, sheds some light on the matter.
在人類社會，還有等級嚴格的其他的靈長類物種中，都已多次驗證這種結果的正確性。但是，雖然這種模式很容易理解，潛在的生物學機制卻并不這么認為。雜志《國家科學院》最新出版的專題里，對此現象有相關闡述。
In it, a group of researchers led by Jenny Tung and Yoav Gilad at the University of Chicago looked at the effects of status on rhesus macaques. Experience has shown that these monkeys display the simian equivalent of the Whitehall studies' findings. The high risk of disease among those at the bottom of the heap in both cases suggests that biochemical responses to low status affect a creature's immune system. Those responses must, in turn, depend on changes in the way the creatures' genes are expressed. To investigate this phenomenon means manipulating social hierarchies, but that would be hard (and probably unethical) if it were done to human beings. You can, however, do it to monkeys, and the researchers did.
專題里，詹妮東和要吉拉德領導的研究小組在芝加哥大學，研究地位之于恒河猴的影響。實驗經過表明，這些猴子所表現出來的是英國白廳研究發現的猴子版本。社會地位低的患病風險高，這既適用于人類界也同樣適用于猴子。這暗示了社會地位低的物種的生物化學反應影響其免疫系統。反過來，這種生物化學反應又取決于物種生物基因的變化方式。若要調查這種現象，那就意味著需要控制社會等級，在人類身上進行，很困難（而且很可能不道德）。但是，你可以在猴子身上做實驗，而且研究人員也是這么做的。
Unhappy minds in unhealthy bodies.
不健康的身體，不快樂的心情。
Dr Tung and Dr Gilad took 49 middle-ranking female macaques (females were chosen because a lot of previous work on animal hierarchies has been done on female macaques) and split them into groups of four or five. The researchers were able to control where in a group an individual ranked by the order in which it was introduced into its group (newly introduced monkeys almost always adopt a role subordinate to existing group members). The hierarchies thus established, the team conducted tests on cells in the monkeys' blood, in an attempt to determine the effect of a macaque's rank on her biochemistry and, in particular, on how rank influences the activity of various genes.
博士東和吉拉德，用49個中等地位等級的女性猴子做實驗（用女性猴子的原因是，前期大量動物地位等級的準備工作都是在女性猴子身上做的），并把他們分為四到五組。根據猴子們加入研究群體的時間順序，研究人員給她們的地位等級編號（新來的都是要聽前輩的，這是潛規則）。等級于是得以建立。研究團隊采集猴子血液做細胞研究，試圖搞清楚恒河猴的地位等級對其生物化學的影響，特別是地位等級是如何對各種基因活動起作用的。
The answer is, a lot. Dr Tung and Dr Gilad looked at the expression in each animal of 6,097 genes (30% of the total number in a monkey genome-or, for that matter, in a human one). They were searching for correlations between social rank and gene activity, and in 987 genes they found one. Some genes were more active in high-ranking individuals; others were more active in low-ranking ones. The relationship was robust enough to work the other way round, too. Given a blood sample and no other information, it was possible to predict an individual's status within her group with an accuracy of 80%.
研究結果有很多。每個動物有6097個基因，博士東和吉拉德觀察每個動物的基因（一個猴子基因組總數的30%??——這也適用于人類），尋找社會等級與基因活動之間的相互關系。在987個基因中，他們找到了一個。某些基因在等級高的個體中更活躍，而其他的基因則活躍于等級低的個體中。這一結果很牢靠，倒過來看也成立。只提供血液樣本而沒有其他相關信息，就可以預測個體在群體里的地位等級，且精確度達到80%。
The next question was what all these genes actually do. Sure enough the answer, for a substantial fraction of them, was that they regulate aspects of the immune system. In particular, low-status individuals showed high levels of activity in genes associated with the production of various immune-related cells and chemical signalling factors, as well as those to do with inflammation (a general immune response that involves tissue swelling and increased immune-cell activity in the affected area). Although the researchers did not explicitly examine the health of their simian charges, chronic, generalised inflammation is a risk factor, in people, for a long list of ailments ranging from heart trouble to Alzheimer's disease.
下一個問題，所有這些基因，真正起的是什么作用。答案很顯然，對大部分基因而言，它們起著調節著免疫系統的作用。這非常明顯地體現在，社會地位低的個體，產生各種與免疫相關的細胞和化學信號基因的活動更為明顯，還有那些有關于炎癥的基因（一種普通的免疫反應，包括細胞組織的膨脹，還有增加免疫細胞在疫區免疫細胞活動）。雖然研究人員沒有仔細分析參與實驗的猴子們的健康狀況，但是慢性的、全身性的炎癥對猴子們來說是危險因素，人類的部分，就是從心臟病到老年癡呆癥等一大長系列疾病。
Finally, the team investigated the mechanisms behind these differences in gene expression. In keeping with previous work, they found that high- and low-rank individuals showed different levels of responsiveness to a class of hormones called glucocorticoids, which regulate immune-system activity and response to stress. They also found changes in the mix of cells within the animals' immune system itself. But what is new, and intriguing, is that they discovered, for the first time, evidence that a phenomenon called epigenetic change is at work.
最后，研究小組用基因表達調查造成這些不同的機理原因。與之前工作結果一致，他們發現地位高和地位低的個體，對被稱為糖皮質激素的一組基因，表現出的反應級別不一樣。糖皮質激素控制免疫系統活動和對壓力的反應。同時他們發現，在動物免疫系統自身，混合細胞有發生改變。但是最為新奇的是，他們頭一次發現了后天改變在起作用的證據。
Epigenetics—currently one of molecular biology's hottest topics—is a process by which genes are activated or deactivated by the presence or absence of chemical structures called methyl and acetyl groups. Dr Tung and Dr Gilad found that methylation patterns were systematically different in high- and low-ranking animals. Crucially, these changes are generally passed on to the daughter cells produced when a cell divides, and are thus perpetuated throughout an animal's life. To the extent that epigenetic marking is involved in creating social status, then, status may be being maintained by the animal's cells as they replicate.
表現遺傳學——目前分子生物學最熱的話題之一——是這樣一個過程，基因的激活或是失效取決于被稱為甲基和乙酰基的化學結構的存在或是消失。博士東和吉拉德發現甲基模式在地位高級和地位低級的動物之間是不一樣的，且這種不一樣是系統性的不一樣。至關重要的一點是，這些變化一般在細胞分裂的同時傳遞給子細胞，因此這些變化將貫穿動物的一生。從此意義上講，后天標記參與社會地位的形成，社會地位的維持靠動物細胞的復制。
Destiny's child?
命運的產物？
Those who believe in progress will, however, be pleased to know that epigenetics is not necessarily destiny. Methyl groups may help maintain the status quo, but if that status quo is interrupted by outside events they can be wiped away and a new lot put in place.
但是，相信事物是發展變化的人們會很高興，因為表現遺傳學并不是上天注定，難以改變的。甲基或許可以幫助維持現狀，但是如果外來事件打斷了它，那么甲基將被移除，新的一批上任。
Dr Tung and Dr Gilad discovered this because a few of their monkeys did change status within their groups. When that happened, changes in gene expression appropriate to the new status quickly followed. Those who do break free from their lowly station, then, may begin to reap the health benefits almost immediately.
博士東和吉拉德能夠發現了這一點，是因為，參與實驗的幾個猴子確實改變了她們在群體中的地位等級。地位等級一旦發生改變，與之相應的基因表達隨即改變。那些確實改變了它們之前卑賤地位的猴子們，身體狀況幾乎都立刻獲得改善。
As with any animal study, this one cannot simply be mapped straight onto humans. But it does provide pointers that researchers who work on people can use. In particular, the experiment ensured that social rank was the only factor being changed, providing strong evidence that the chain of causality runs from low social status, through a disrupted immune system to worse health, and not the other way around. The best medicine, then, is promotion. Prosper, and live long.
不管以什么動物為研究對象，結果都不能直接簡單地運用于人類，這個也不例外。但它確實給研究人類的學者們提供了一些建議。該實驗的獨特之處是，它確保了實驗中社會等級是唯一發生改變的因素。它為因果關系鏈的正確模式提供了一個強有力的證據，正確模式是低等的社會等級通過被破壞了的免疫系統損害健康。而不是反過來的順序。晉升是療效最好的藥物。因為成功，所以活得長久。
