ONE INEQUALITY STARTS AT HOME An Introduction to the Pecking Order Let me start with a story. Once upon a time a future president was born. William Jefferson Blythe IV entered the world one month premature but at a healthy six pounds and eight ounces. At twenty-three, his mother, Virginia, was young by today''s standards, but perhaps a touch old for Arkansas in the 1940s. She was a widow, so times were tight during Bill''s early years. In fact, times would be tough during all of Bill''s childhood. Nonetheless, he seemed destined for great things. According to family lore, in second grade Bill''s teacher "predicted that he would be President someday.

"[1] His mother eventually married Roger Clinton, but that didn''t make life any easier for Bill. Roger was a bitterly jealous alcoholic who often became physically abusive to his wife. Bill cites the day that he stood up to his stepfather as the most important marker in his transition to adulthood and perhaps in his entire life. In 1962, when Bill was sixteen, Virginia finally divorced Roger, but by then there was another Roger Clinton in the family, Bill''s younger half brother. Though Bill despised his stepfather, he still went to the Garland County courthouse and changed his last name to Clinton after his mother''s divorce from the man--not for the old man''s sake, but so that he would have the same last name as the younger brother he cherished. Though they were separated by ten years, were only half siblings, and ran in very different circles, the brothers were close. The younger Roger probably hated his father more than Bill did, but he nonetheless started to manifest many of the same traits as he came of age. He was a fabulous salesman: at age thirteen, he sold twice as many magazines as any of his classmates for a school project, winning a Polaroid camera and a turkey for his superior effort.

He also had an affinity for substance abuse: by eighteen, he was heavily into marijuana. During Bill''s first (unsuccessful) congressional campaign in 1974, Roger spent much of his time stenciling signs while smoking joints in the basement of campaign headquarters. As Bill''s political fortunes rose, Roger''s prospects first stagnated and then sank. He tried his hand at a musical career, worked odd jobs, and eventually got into dealing drugs. And it was not just pot; in 1984, then-governor Bill Clinton was informed that his brother was a cocaine dealer under investigation by the Arkansas state police. The governor did not stand in the way of a sting operation, and Roger was caught on tape boasting how untouchable he was as the brother of the state''s chief executive. Then the axe fell. After his arrest, Roger was beside himself in tears, threatening suicide for the shame he had brought upon his family--in particular, his famous brother.

Upon hearing this threat Bill shook Roger violently. (He, in truth, felt responsible for his brother''s slide.) The next January, Roger was sentenced to a two-year prison term in a federal corrections facility in Fort Worth, Texas. Bill describes the whole ordeal as the most difficult episode of his life. David Maraniss--the author of First in His Class, the most comprehensive biography of Clinton to date--summarizes the family situation as follows: How could two brothers be so different: the governor and the coke dealer, the Rhodes scholar and the college dropout, one who tried to read three hundred books in three months and another who at his most addicted snorted cocaine sixteen times a day, one who could spend hours explaining economic theories and another whose economic interests centered on getting a new Porsche? In the case of the Clinton brothers, the contrasts become more understandable when considered within the context of their family history and environment. They grew up in a town of contrast and hypocrisy, in a family of duality and conflict. Bill and Roger were not so much opposites as two sides of the same coin.[2] If asked to explain why Bill succeeded where Roger failed, most people will immediately point to genetic differences.

After all, they were only half siblings to begin with. Others will pin it on birth order, claiming that firstborns are more driven and successful. But both of these accounts rely on individual explanations--ones particular to the unique biology or psychology of Bill and Roger--and both are incomplete. Was Bill more favored and more driven because he was a firstborn? My research shows that in families with two kids, birth order does not really matter that much. In fact, just under one-fourth of U.S. presidents were firstborns--about what we would expect from chance. The fact is that birth position only comes into play in larger families.

But what about genes: was Bill simply luckier in the family gene pool? That may be so, but it still does not explain why sibling disparities are much more common in poor families and broken homes than they are in rich, intact families. In fact, when families have limited resources, the success of one sibling often generates a negative backlash among the others. Sure, if one kid is born a mathematical genius and the other with no talents whatsoever, their respective dice may be cast at birth. But for most of us, how genes matter depends on the social circumstances around us. A child in one family may be born with innate athletic talent that is never nurtured because the parents in that family value reading ability over all else. Yet in another family, the fit between the individual talents of a particular child--say spatial reasoning--and the values of the parents may be perfect, and those abilities are realized. Finally, what kind of rewards talent brings depends entirely on the socioeconomic structure of the time. Fifty years ago, musical talent might have led to a decent living.

Today--in an economy that rewards the most popular musicians handsomely at the expense of everyone else--innate musical ability is more often a route to financial struggle. In Bill Clinton''s case, he obviously had good genes--which contributed to his sharp mind, quick wit, tall stature, and verbal charisma--but there was not much advantage to being the firstborn. What really made a difference in his life was the good fit between his particular talents, the aspirations of those around him, and the political opportunities in a small state like Arkansas. This good fit combined with his family''s lack of economic resources to generate an enormous sibling difference in success. However, had Virginia had money, she might not have had to put all her eggs--all her hopes and dreams--in Bill''s basket. She might have been able to actively compensate for Bill''s success by giving Roger extra financial and nonfinancial support--sending him, for example, to an elite private school when he started to veer off track. Instead, Bill''s success seemed to come at the expense of Roger''s--particularly when it led Roger to a false sense of invincibility. On the surface, it may seem that the case of the Clintons is atypical.

And, of course, a pair of brothers who are, respectively, the president and an ex-con is a bit extreme. But the basic phenomenon of sibling differences in success that the Clintons represent is not all that unusual. In fact, in explaining economic inequality in America, sibling differences represent about three-quarters of all the differences between individuals. Put another way, only one-quarter of all income inequality is between families. The remaining 75 percent is within families.[3] Sibling differences in accumulated wealth (i.e., net worth) are even greater, reaching 90-plus percent.

[4] What this means is that if we lined everyone in America up in rank order of how much money they have--from the poorest homeless person to Bill Gates himself--and tried to predict where any particular individual might fall on that long line, then knowing about what family they came from would narrow down our uncertainty by about 25 percent (in the case of income). In other words, the dice are weighted by which family you come from, but you and your siblings still have to roll them. For example, if you come from a family that ranks in the bottom 5 percent of the income hierarchy, then you have a 40 percent chance of finding yourself in the lowest 10 percent, a 21 percent chance of making it to somewhere between the 30th and 70th percentile, and only a one in a thousand chance of making it to the top 10 percent. If you come from the richest 5 percent of families in America, then your odds are flipped. And if you start at the dead middle of the American income ladder, then you are about 63 percent likely to end up somewhere in that 30th- to 70th-percentile range, with a 4 percent chance of ending up either in the top or the bottom 10 percent.[5] A similar pattern holds for educational differences. For example, if you attended college there is almost a 50 percent chance that one of your siblings did not (and vice versa).[6] What do sibling disparities as large as these indicate? They imply an American landscape where class identity is ever changing and not necessarily shared between brothers and sisters.

Taken as a whole, the above statistics present a starkly darker portrait of American family life than we are used to. We want to think that the home is a haven in a heartless world. The truth is that inequality starts at home. These statistics also pose problems for those concerned with what seems to be a marked erosion of the idealized nuclear family. In fact, they hint at a trade-off between economic opportunity and stable, cohesive families. While it may be surprising to realize how common sibling inequality is on the whole, my analysis of national data shows that Americans are quite aware of sibling disparities within t.