When I was a child growing up in England three decades ago, I was confronted with the visual evidence of social mobility every day – but of the downward, not upward, type.

30年前，当我还是个孩子的时候，我住在英格兰，每天都目睹表明社会流动性的“视觉”证据，不过流动方向是向下的，而不是向上的。

We lived in a suburban, middle-class home. On the walls, however, hung the portrait of an 18th-century Anglo-French aristocrat, a maternal ancestor. In the intervening centuries, my aristocratic forebears had lost their status and wealth due to drink, gambling and poor decisions. Thus, my only link with royalty was that portrait and the fact that I have the same unusual middle name – Romaine – as the noblewoman in the picture.

我们是生活在郊区的中产阶级之家。但家里的墙上挂着一幅18世纪英法贵族的画像，她是我母亲家族的一位祖先。从她往后的几个世纪里，我的贵族祖先们由于饮酒、赌博和一些糟糕的决定而失去了地位和财富。因此，我与贵族仅有的联系就是那幅画像，以及我有一个不同寻常的中间名罗曼(Romaine)，与画像中的贵妇一样。

A rare example of social mobility or a widespread pattern? Today, that is a very politically charged question, particularly in countries such as the US. But it is also a very hard question to answer definitively.

这是社会流动性的一个罕见例子，还是一种普遍模式？如今，这是一个充满政治意味的问题，尤其是在像美国这样的国家。但这个问题很难明确回答。

Social mobility is an issue about which politicians love to pontificate but about which we actually know surprisingly little. Economists have generally tracked mobility by looking at surveys on wealth, jobs and educational attainment over two or three generations. This has typically shown that mobility is highest in the Scandinavian countries and lowest in places such as Latin America, with the US and UK lying halfway in between.

社会流动性是政治人士喜欢夸夸其谈的一个问题，但实际上我们对它的了解出奇地少。经济学家一般通过考察两、三代人的财富、就业和教育程度来追踪社会流动性。这些研究一般表明，斯堪的纳维亚国家的社会流动性最高，拉美等国最低，美国和英国介于二者之间。

Interestingly, these surveys tend to show that more mobile societies such as Sweden are also more equal, as determined by the Gini coefficient, the most commonly used measure of inequality, and vice versa. The idea that you can justify high levels of inequality in some nations because there is plenty of mobility – as US politicians are apt to do – does not ring entirely true, based on the economic numbers.

有趣的是，这些调查往往表明，瑞典等社会流动性较大的国家也更为平等，与基尼系数（Gini coefficient，最为常见的衡量不平等程度的指标）所显示的一样，反之亦然。有人认为，可以把一些国家的高度不平等说成合理的，因为它们的社会流动性很大——美国政客就经常这么说。但根据经济数据，这种看法并不完全正确。

The problem with this widely cited economic data are that they are very limited: it typically only tracks families over a generation or two and cannot capture subtle social patterns. So Gregory Clark, an economic historian at the University of California, Davis, has recently attempted to use another innovative approach that blends sociology, economics and history. In a new book, The Son Also Rises, he has analysed surnames in historical databases around the world to work out how families have risen in terms of wealth and status over multiple generations. In the US he looked at doctors; in the UK, at elite universities such as Oxford and Cambridge; and in Sweden, land records.

这些被普遍引用的经济数据的问题在于，它们非常有限：它们对家族数据的追踪通常仅限于一、两代人，无法捕捉微妙的社会模式。因此，美国加州大学戴维斯分校(University of California, Davis)经济历史学家格里高利•克拉克(Gregory Clark)最近尝试运用另一种创新方法，把社会学、经济学和历史学结合在一起。在其新书《虎子崛起》(The Son Also Rises)中，他对全球历史数据库中的姓氏进行了分析，考察家族财富和地位是如何在好几代人时间内上升的。在美国，他考察了医生；在英国，他考察的是牛津(Oxford)和剑桥(Cambridge)等精英大学；在瑞典，他考察的是土地记录。

This approach – like the econometric one – has its limits. Historical lists of surnames or elite jobs can be patchy, particularly since they are dominated by the paternal line. (My story of maternal downward mobility, for example, would have been missed.) But Clark reaches some thought-provoking conclusions. First, he argues that if you look at multiple generations, social mobility is lower than widely presumed in most nations. Second, there is less difference between nations than usually thought. Those “egalitarian” Swedes are not as mobile as presumed. But in America, Clark rejects the idea that mobility has recently declined sharply as social polarisation has grown – an idea posited, for example, in Coming Apart, an influential book published last year by the political scientist Charles Murray. Clark argues that mobility is indeed low in America but insists it has always been thus.

这种方法（类似计量经济学方法）有其局限性。姓氏或精英职业的历史清单可能是不完整的，尤其它们主要是父系数据。（例如，我母亲家族的向下流动会被遗漏。）但克拉克得出了一些发人深省的结论。首先，他主张，如果从好几代人的数据来看，多数国家的社会流动性低于人们普遍的想象。其次，国家间的差异小于人们通常的想象。“主张平等”的瑞典人的社会流动性并不像人们想象的那样大。但对美国，克拉克并不同意以下观点：由于社会两级分化现象加剧，社会流动性最近大幅下降——这是政治学家查尔斯•默里(Charles Murray)去年出版的颇具影响力的著作《分化》(Coming Apart)中的看法。克拉克指出，美国的社会流动性确实很低，但他坚持称，该国一直如此。

. . .

第三，克拉克表示，社会秩序的稳定性揭示了其他事实：真正决定地位的是“本性”（即从父母身上遗传的才能）而非“教养”（即国家干预或父母影响）。或者换句话说，克拉克认为，一些家族历经几代人仍保持精英地位的原因是，家族成员遗传了精英性格特征和技能，使他们更有能力竞争。

Third, Clark says that the stable nature of the social order reveals something else: it is “nature” (ie the level of inherited talent from both parents), rather than “nurture” (ie state intervention or parental influence) that really determines status. Or to put it another way, Clark thinks that the reason people retain elite status over generations is that they inherit elite character traits and skills which enable them to compete better.

毫不意外的是，最后一种看法令一些美国评论人士感到震惊，他们认为，这种观点与种族主义一样荒谬。我倾向于认为，如果精英地位可以延续很多代人，这与DNA关系不大，而是更多在于我们不经意间从父母那里遗传的微妙文化模式和认知地图。正如美国专家大卫•布鲁克斯(David Brooks)在他的精彩著作《社会动物》(Social Animal)中所指出的那样，我们都是所处社会环境的产物，或者用法国学者皮埃尔•布尔迪厄(Pierre Bourdieu)的术语来说，我们是“习惯”(habitus)的产物。财富通常会带来权益和更多财富（不过也不一定，就如我家的“罗曼画像”所显示的）。

Unsurprisingly, this last idea appals some American commentators, who equate it to racism. I tend to think that if elite status is retained over many generations, it says less about DNA and more about the subtle cultural patterns and cognitive maps that we inherit, unthinkingly, from our parents. As the US pundit David Brooks pointed out in his brilliant book The Social Animal, we are all creatures of our social environment (or our “habitus”, to use the terminology of Pierre Bourdieu, the French intellectual). Wealth generally begets entitlement – and more wealth (albeit not always, as my “Romaine portrait” shows).

然而，不管你对克拉克有关遗传“天赋”的观点喜欢与否，有一点不容置疑：我们需要更多地思考社会流动性，尤其是在一个政客用它来将不平等合理化的世界里。那些有关一夜成功的坊间故事可能会让人相信美国梦，或者能够让英国人声称，唐顿庄园(Downton Abbey)里的阶级分化早已一去不复返。但我们迫切需要展开更多研究，将社会和经济趋势联系起来。随着更多数据变得“数字化”，以及人们通过家谱网站（或者甚至通过墙上的画像）开展自己的研究，让我们期待，这会成为现实吧。

But whether you love or hate Clark’s ideas about inherited “talent”, it is indisputable that we need to think more about mobility, particularly in a world where politicians use it to justify inequality. Anecdotal tales of sudden success might support the American dream or enable British people to claim that the stratification of Downton Abbey is long gone. But there is a crying need for more research that links social and economic snapshots. Let us hope this does emerge, as more data become “digitised” and people do their own research via genealogy websites. Or even via portraits on walls.