Oh, Brother!

He set the standard for my lifelong attraction to younger men," says Isadora Alman of her brother, her only sibling, 5 ½ years her junior. "I can't remember one occasion on which we fought. If one of us was to be punished, the other would immediately jump in: 'Oh, no, it was my fault.' Our relationship became part of the way I love people."

Of course, Alman notes, "It helped that we never lived under the same roof after I turned 13 and went off to boarding school" and that they now live on opposite coasts. It also helped that her baby brother was promised to her. "He was my baby. I was prepared for him. There was no sense of competition."

Their bond is sealed by something unquantifiably stronger than genes or geography—a shared sense of the absurd. "We're both word people," she explains. So the emails they exchange once or twice a week revel in outrageous puns and the verbal mishaps of others.

As a marriage and family therapist in Alameda, California, Alman knows from countless hours in the consulting room that she and her brother are lucky exceptions. Sibling strife is often the rule, at least at some point in life.

Not only may parents treat young offspring unequally, giving rise to sibling resentments that can long outlast the parents themselves, there is evidence that competition among siblings to distinguish themselves from each other is an inevitable—and necessary—part of family life. Sibling strife allows for the emergence of distinct personalities and identities.

Despite siblings' power to inflame, they are the longest-lasting relationships many of us ever have. Others may help us become who we are, but no one else knows us from the beginning to the end, and that longevity can be humbling. Whether siblings cycle through our lives or call every week, we are almost always conscious they are there. We carry deep within a sense of shared fate. What's more, often quite unthinkingly, we tend to replicate our roles relative to them in work and even love. Whether we like them or not, siblings are forever.

The Sibling Trajectory

The 82 percent of Americans with siblings typically spend their early years interacting with each other far more than with outsiders. That changes as they grow, expand their range of contacts, and hit new stages of development. In early adolescence, the sibling bond naturally sheds some of its intensity as exciting new relationships open up outside the family and intimacy takes a great leap forward with agemates of both sexes. In early adulthood, siblings—especially sisters, bound by their penchant for self-disclosure—may come together to share resources.

As siblings get beyond their 20s, pair off with partners, move, and establish their own families, the bond generally goes into hibernation. "It's not a key relationship even if you like each other," reports Heidi Riggio, assistant professor of psychology at California State University Los Angeles. "We care; it's just that we're so busy raising our families." Distance becomes more a determinant of sibling emotional closeness. Unless, of course, there's a crisis.

At 44, Shanley Wells is the oldest of three. "Because of our age distribution—my brother and sister are five and six years younger—we seemed to be raised in two different families," she reports. "Our memories are different, our knowledge of our parents is different—but we did have the same parents!" Wells grew up in a traditional family with a stay-at-home mother. But when she was in college, her father left, and her siblings grew up with a single, working mother. One result, she says, is that her sister became a strong feminist.

Wells was not close to her siblings growing up in Memphis. "They were close in age and knew a lot of the same people. I always felt out of the loop." To her, both siblings were "a general annoyance. We fought a lot. For years my brother and I had our younger sister convinced that she was bought at a children's farm in Kentucky. He even drew up a certificate of purchase." Wells believes that in taking their frustrations out on each other, she and her siblings were reflecting the tensions in their parents' marriage.

Nor was Wells a role model for her siblings: "I was angry and rebellious." Wells moved to the Midwest. Ten years ago, her sister also moved to the Midwest, and the two became much closer. "I felt more secure," Wells confides. "I had my own sense of self. What happened when we were kids didn't matter anymore." Eventually, their brother also moved to the Midwest.

And then last year, their mother died, totally unexpectedly, at a relatively young 68. "That pulled us together," Wells reports. "Formerly, we all stayed in touch through my mother. But my brother, busy with his work and children, has vowed not to let life whiz by without contact. He's really trying. We now have a plan to all travel together, with our spouses, once a year.

The Long Arm of Influence

Sibling relations are so durable because they are close—"often uncomfortably close," in the words of British developmental psychologist Judy Dunn. What's more, they are children's first relational experiences, the ones that shape their social and self-understanding for life. And without any prompting from adults, they tend to be highly emotion-ally charged. They turn everyday family life into a daily drama for young ones, each of whom is vying for a starring role.

No one has limned this territory better than Dunn, professor of child development at the Institute of Psychiatry in London, who has studied siblings in their natural habitat, the home. Starting from a very early age—before 12 months—children exhibit a highly sophisticated social understanding.

They are extraordinarily sensitive to differences in affection, in warmth, in pride, in attention, and in discipline that parents dole out. They are virtually born attuned to the emotional exchanges going on around them. "They keep an eagle eye out for differences on how all siblings are treated, and they are quick to pick up differential treatment. What's more, they have notions of whether the treatment they or their siblings get is fair or unfair."

Not only are young children aware of what is going on between their siblings and their parents, they are often profoundly influenced by that dynamic. Dunn's longitudinal studies show that children who feel that they are on the short end of maternal affection and attention relative to siblings (maternal treatment seems to carry more weight than paternal treatment) become worried, anxious, or depressed, as their experiences of deprivation become incorporated into their evaluations of themselves.

And make no mistake, Dunn has found that children as young as two are already incorporating social comparisons into self-appraisals. Further, the greater the perception of differential treatment, the more conflict and hostility marks the sibling relationship. Perceptions of unfairness are also linked to adjustment difficulties, such as contrariness and problems with peers outside the family. These patterns of relating to others can remain remarkably stable over time.

What's even more startling, says Dunn, is that in families where children perceive marked differences in parental treatment, the children experience problems in adjustment—whether or not they are the disfavored one. They have difficulties in relationships. "Yet children are so different, it's hard to treat them the same," Dunn says. "This is the paradox of child development."

Even as adults, people monitor what their siblings get. "I see it with my own grown sons," confides Dunn. "They'll come for a meal and notice which one is getting the most potatoes." Early on, kids develop their own accounts of differential treatment, and "they carry that mythol-ogy around through life." One child, for example, may always escape trouble because parents see him as "the good kid." But siblings are likely to explain it quite differently—they might conclude that he's always trying to sneak around the rules.

Differential treatment by parents is only one factor affecting the durability of the early sibling environment. "Most important is the temperament of each child," says Dunn, how edgy or irritable they are. Openness to experience and flexibility are also key determinants.

What strikes Dunn most is how different the family environment is for each child in the same household. And that helps account for how siblings turn out so different. Children only seem to share the same home. In reality, "they inhabit different microenvironments," influenced by age, power, understanding, sensitivity, parental treatment, and the relationships between siblings. The same experience impacts them differently.

Dunn has found that fewer than a third of siblings even show the same degree of affection towards each other. Even such alleged major influences on children as a mother's mental health may impact siblings differently if, say, one child has a strong relationship with a grandparent.

Carving Out a Place for Me

Sibling relationships tend to be lasting because children develop strategies to compete with each other for parental attention, and that learning becomes encoded in personality, contends Frank Sulloway, a historian of science and psychologist who is a visiting scholar at the University of California at Berkeley. Best known for his investigation of the effects of birth order, Sulloway sees sibling relationships through a starkly Darwinian lens.

Humans are hardly unique, Sulloway insists. "Sibling rivalry is widespread among animals whose young receive parental care, and in this sense it is largely hard-wired." Siblings are a lot like Darwin's finches, not merely highly diverse but driven to find a niche in the sometimes crowded terrain they're born into.

For humans, that's the family environment, and they use their brains—those precociously socially sensitive instruments—instead of their beaks to distinguish themselves one from another, a process known as de-identification. Taking on different family roles based on such factors as age, sex, personality, interests, and ability, they embody the prime evolutionary principle of divergence in order to snare as much parental support as possible.

In Sulloway's view, birth order is one of the major factors driving sibling diversification. Exposed to exclusive parental attention in their earliest years, firstborns, he says, are often most expected to uphold family values and traditions and act as surrogate parents (especially oldest females), fostering the development of conscientiousness. The role of the responsible one may continue well into adulthood, with achievement orientation and expectations that they provide advice and even economic assistance to laterborns.

Lastborns, too, get some privileged parental attention, but by the time they arrive so many family niches are taken they have little to lose by rejecting parental values and becoming risk-takers. Unconventional and even rebellious, they are most likely to be extraverted and open to new ideas. Most political and scientific revolutions, Sulloway contends, are started or championed by lastborns—Copernicus was the youngest of four, Darwin himself the fifth of six children.

Birth order, Sulloway insists, is really proxy for family roles, predicted most by sibling differences in age and the attributes that go along with it, such as size, power, verbal mastery, and overall maturity. For siblings who are closest in age, de-identification is most urgent, forcing siblings adjacent in the family constellation to develop opposing personality traits.

Even if parents go out of their way to ensure that all their kids get equal attention, middle children still lose. "They receive less cumulative investment than do eldest and lastborn offspring," Sulloway says. And that explains why they go through life with lower self-esteem, feel more self-conscious, and often feel closer to friends than to parents.

Sometimes disposition trumps birth order in shaping sibling relationships. E.G. Sebastian and his brother, younger by two years, didn't have to seek niches for themselves. Their temperaments took care of that. Growing up in Romania, Sebastian found himself drawn to nature from the start. "Swimming in the river was forbidden, but I swam in it nearly every day, even though my parents spanked me. I rarely did homework and often skipped school. In elementary school, I was a C/D/F kind of kid." His brother, on the other hand, got straight As. "He was conscientious. He cared about school."

There was little competition. Once, as an adult, he happened upon the diary his brother kept as a teenager. "I was surprised to find that his philosophy, his thinking was close to mine." It's just that their personal styles were so different.

"I'm a risk-taker," Sebastian says. "I do things first and think later. He is cautious and overthinks everything. I love to travel. He doesn't; he loves security." The risk-taking Sebastian began an import-export business based in Budapest. He gave it up after he came to visit his brother—who, with their parents, had emigrated to the U.S.— and wound up falling in love and staying in the U.S. The brothers now live about 60 miles apart in the South Carolina low country and visit often. "We are very close, but we are still very different."

Blame Mom, Not Me

As every adult knows, some sibling strategies remain strictly situational, not necessarily incorporated into personality or carried into the world outside the family. (Think whining.) The staying power of sibling strategies accounts for what could be called the Thanksgiving Effect—the tendency of fully functional adults to find themselves drawn, often against their own will, into long-abandoned but still emotionally charged childhood roles at family gatherings.

The imprint of the early family environment tends to run deep because it is a habitual way of thinking about self and others. Few are aware of slipping into an old behavior pattern until it creates unbearable distress. You never measured up at home compared to an older sibling? You may find yourself drawn to a spouse or a boss who is difficult to please.

It's not fatalistic to think that family position structures relationships, Michael Kerr insists. Kerr, head of the Bowen Center for the Study of the Family in Washington, D.C., maintains that thinking about sibling position actually provides a good way to turn unpleasant sibling relationships around in adulthood. A change of heart occurs when people realize that animosity is not innate to the warring individuals but was set up in the relationships with parents.

This insight helped three brothers who were deadlocked in trying to settle a large family estate. The oldest and middle siblings were at odds over how to value several properties. The oldest was crippled with anxiety because he felt responsible for the outcome, while the second brother felt uncompromisingly entitled to his point of view. Kerr got the men to see that their polarization replicated their relationship with their mother. That allowed the oldest to move away from criticism of his brother while it melted the second brother's attitude, and a compromise was forged.

An End of Life About-Face

Because family roles tend to get encoded in personality and identity, it can take a huge amount of work to develop new patterns of relating to siblings in adulthood. Some universal situations, however, can serve as crucibles in which to recast relationships. In most families, the moment of truth for adult sibling relationships is the aging of parents and decisions about end-of-life parental care.

Such situations not only force siblings into contact but usually require agreement. In some families, the siblings are able to drop their old animosities and adopt a mode of care that is not unfairly burdensome to any one sibling. Other families fracture on the fault lines set decades earlier.

If parental care doesn't make or break siblings, then inheritances certainly do, given the power of final parental dictates to codify inequities in the cold calculus of cash. But for Isadora Alman and her brother, the inheritance only cemented closeness.

"Our father's death was unexpected. My brother traveled across the country for the reading of the will. In it, our father forgave all debts but left my brother and me with very little and strangers with a lot. My brother and I were sitting on opposite sides of the room, but we looked at each other—and laughed at the irony of what a strange guy our dad was. We both got equally screwed."

In the long view, sibling conflict is necessary, inevitable, and an instrument of self-definition that has a correctable course over time. But parents often subscribe to a short view: They prefer peace in the house. They want their children to be close (or at least quiet). What's more, parents invariably claim they treat their kids equally, even though children can't possibly experience their care equally, as they are at different levels of understanding.

Parents are quick to deny differential treatment of their kids, says Cal State's Heidi Riggio, because it is difficult and painful for them to think about how they may have failed their children, whose experiences of favoritism are incorporated into identity. "In another culture," she adds, "parents may be willing to admit they treated the eldest son best. But not in America, with its ethos of fairness and equality."

"But if there's no conflict," says family therapist Diane Barth, "then it's not possible for siblings to move on to being more connected as adults. Theirs becomes an artificial relationship." It is the same kind of misunderstanding that believes happiness admits no ripple of discomfort. When siblings learn to fight and to master their own conflicts, Barth explains, that is a formula for resolving conflicts for the rest of their lives. And that's the real path to lasting peace.