For some in the hard sciences, it was difficult to fathom: a sociologist winning the US National Science Foundation's A. T. Waterman award for achievement by a young researcher? Surely there must be some mistake. But in his acceptance speech last month, Dalton Conley was far from defensive about his discipline's status. “I would like to argue that sociology is among the hardest sciences of all — harder than the proverbial rocket science,” he told a black-tie gathering in Washington DC.

Mix it up: a childhood steeped in contrasts of race and class helped shape Dalton Conley's work. Credit: K. ALFORD/PANOS PICTURES

Controlled experiments are out, Conley reminded the assembled scientific leaders, and causality is often masked by a confusing tangle of variables. And as if that wasn't difficult enough, sociologists' subject matter includes “the most politically charged and most personally sensitive topics one could address”. Some researchers respond to the challenges by retreating into largely descriptive approaches, but Conley has won respect for applying rigorous, quantitative methods. He is the first sociologist to win the prestigious Waterman prize, worth a handsome $500,000.

Weeks after the award ceremony, in the Washington Square office where he directs New York University's Center for Advanced Social Science Research, Conley says he hasn't decided what to do with the prize money. But relaxing in a room comfortably cluttered with books — including the four he's already written by the tender age of 35 — he is happy to elaborate on the message of his speech. “A lot of the most interesting social science tries to push beyond descriptive accounts of how the world looks and get into causal accounts of how it works,” Conley explains. But lacking the ability to manipulate variables the way a physicist or chemist would, “you have to look for tricks, natural experiments”.

I like to squeeze a little bit more out of the lemon after everyone else has squeezed it. Dalton Conley, Center for Advanced Social Science Research, New York

When it comes to finding clever new ways to mine sociological data, Conley admits to being competitive. “I like to squeeze a little bit more out of the lemon after everyone else has squeezed it,” he says. One database he's squeezed particularly hard is the Panel Study of Income Dynamics (PSID), a longitudinal study of nearly 8,000 US families. The PSID, administered by the University of Michigan, has been following the same families and individuals since 1968, the year before Conley was born, collecting a wide range of data on their economic status, health, work and family life.

The research problems that interest Conley most have to do with accidents of birth such as skin colour and body size, and how they can affect not just one person, but a whole family tree. His research has advanced our understanding of race and class. And given Conley's own early upbringing on a low-income housing project, he can claim more street credibility than most of his academic colleagues. But what really separates Conley from his peers is his sophistication in analysing multiple variables to tease out underlying, and sometimes unexpected, patterns.

He has used the PSID to ask who gets ahead and who doesn't in America, and he is especially good at weeding out factors that distract from the real story, such as current annual income. Net worth, he has found, is a much better measure of the resources available to a person, since it captures wealth handed down from earlier generations. As Conley reported in his 1999 book Being Black, Living in the Red: Race, Wealth, and Social Policy in America, this accumulated wealth is crucial in determining future economic success.

In black and white

Conley's diligent number-crunching has also provided new insights into the real differences — or lack thereof — between races. While studies have consistently shown that African Americans are more likely to drop out of high school and college, most have ignored the fact that a typical white family has eight times the accumulated wealth of its black counterpart. When Conley applied statistical techniques to remove the variable of family wealth, the most recent cohort of African-Americans in the PSID was actually more likely to graduate from high school than were whites. In an economy where wealth begets wealth, this could be significant for social policy. Indeed, Conley's data lead him to suggest that affirmative action should be based on economic class instead of race.

Credit: K. ALFORD/PANOS PICTURES

He hasn't come out in favour of paying reparations to the descendants of slaves to right the economic wrongs still being visited upon them — as divisive a topic as one can imagine in American politics — but he doesn't dismiss the argument out of hand. Even if society won't make such payments, he notes, doing the numbers is still worthwhile to point out the real costs of unequal opportunity.

Conley's own background provided an education in race, class and the dickensian twists and turns that a life can take. Born to middle-class white parents, he grew up — in part due to his parents' bohemian preferences — in a low-income neighbourhood where nearly everyone else was black or Latino. It was a rough environment, in which a playground quarrel could end with a knife being pulled. When he was 13, a black friend was paralysed by a ricocheting bullet, a traumatic experience that left Conley with an obsessive-compulsive disorder that lasted into adulthood.

Divided lives

Even as a child, however, Conley was aware that he enjoyed privileges that his playmates didn't share. His parents were able to navigate their children through New York City's inequitable educational system — he went to a mostly white, upscale school in Greenwich Village a few blocks from his current office; his own two children attend the same school today. Rather than ending up in a gang like some of his friends, Conley was a semi-finalist in the high-school Westinghouse Science Talent Search. Although he claims never to have made a conscious decision to investigate the factors that shaped his own life, and those of his childhood friends, today he says that it's obvious to him why he later gravitated towards the study of race and class.

As an undergraduate at the University of California, Berkeley, Conley briefly considered a career in biomedical research, before deciding too much of the work he saw was “all trees and no forest”. While conceding that sociology can sometimes suffer from the reverse problem, he has no regrets about his chosen field, which allows him to apply quantitative rigour to vexing social questions.

Conley examined one such question — the consequences of birth order — in his 2004 book The Pecking Order: Which Siblings Succeed and Why. It's not as simple as the firstborn always wins, he has found. In fact, using data from the PSID, the General Social Survey and the US Census, Conley concludes that birth order only really counts in families with more than two children — and that external societal and economic pressures play a larger role than expected. Poor people with larger families, he suggests, often are forced to make hard decisions about which children to invest their time and money in — decisions that wealthier parents can avoid.

Lately, Conley has become interested in how body size affects economic fortunes. Using the PSID to include data on older women than other studies have considered, he finds that being overweight leads women to have less workplace prestige, whereas overweight men suffer no such problems. Overweight women also have lower family income, are less likely to get married, and are more likely to be divorced, separated or widowed.

Just add genetics

Conley has always been interested in how biological and social factors interrelate, and he sees big research opportunities in combining genetic and sociological data. Social scientists have been rightly sceptical of the easy explanations for human differences offered by some geneticists, says Conley. “But they're standing on the sidelines carping like little yappy dogs,” he argues. “We need to dive headfirst into this.” To Conley, genetic differences are just another variable to throw into the mix along with socioeconomic factors.

While many sociologists prefer to think of their field as one of the humanities rather than a science, Conley seems happy either way. Narrative is central to his work, and his books blend quantitative arguments with personal stories. Having written a childhood memoir, Honky, at 30, he says he may someday try his hand at a novel, and he alternates writing scientific papers with popular books and op-ed pieces. Sally Hillsman, executive officer of the American Sociological Association, calls Conley “perhaps the most impressive sociology scholar of his generation”, while comparing him to Carl Sagan and Stephen Jay Gould in his ability to communicate to a wider audience.

But even with Conley's gift for mixing storytelling and statistics, sociology can never fully account for all of the variables that shape an individual's life. As he wrote in The Pecking Order: “Anyone who tells you that they are going to explain your personality, your marriage, your career, or anything else about you with one factor — gender, birth order, income, or astrological sign — might as well be selling you a bottle of snake oil.” Conley is no snake-oil salesman, and in that book advocated a more nuanced approach to studying who succeeds, and why: “And just maybe — along the way — we will have a little more sympathy for our less fortunate brothers and sisters.”