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Interview With Jeffrey Kluger, Author of 'The Sibling Effect'

Love and rivalry in the family

Growing up in a boisterous four-boy household, Jeffrey Kluger experienced the power struggles, jockeying for parental attention and mutual protectiveness common among siblings. But his views of both sibling rivalry and sibling love were complicated by family dysfunction and breakdown.

See also: Excerpt from The Sibling Effect.

Four boys in bathtub - Jeffery Kluger author of The Sibling Effect - sibling birth order

Photo by Dennis Hallinan/Getty Images

Birth order is just one contributing factor in the quality of siblings' adult relationships.

"My own life has in some ways been a decades-long tour of the sibling experience," Kluger writes in The Sibling Effect: What the Bonds Among Brothers and Sisters Reveal About Us. "I have full sibs, I have half-sibs, and for a time I had step-sibs. My family went through divorces and remarriages and the later, blended home — and then watched that home explode, too." His brothers pulled together to weather family crises, including their mother's prescription-drug addiction, and developed close ties with half-siblings, whom they came to know only as adults.

Kluger, a senior editor and writer at Time magazine, weaves these personal stories into a lively overview of contemporary family research. The Sibling Effect discusses the effects of birth order, the upside of playroom rivalries, the impact of divorce and blended families, the closeness of twins, and how siblings function as adults. As many of us outlive parents and spouses, he writes, the only family we'll have will be "the brothers and sisters who have been with us the longest, loved us the hardest, and, by a wide margin, know us the best."

Kluger spoke to the AARP Bulletin about his book.

Q. What is the sibling effect?

A. The sibling effect is the profound power your siblings have to shape who you are and who you become. Your parents leave your life all too early; your spouse and your children don't come along until much later. Your siblings are with you throughout the entire journey. Sisters have ways of socializing brothers into the mysteries of girls. Brothers have ways of socializing sisters into the puzzle that is boys.

Q. What other influences do siblings have on one another?

A. Siblings can train one another, unfortunately, into risky behavior in all kinds of areas — drugs, alcohol, smoking, even teen pregnancy. But the upside is, siblings who avoid those problems can help socialize their younger siblings to avoid them as well. Most important, the battles that you fight in the playroom are very much dress rehearsals for the way you live your life later.

Q. Why was sibling research neglected for so long?

A. Scientists often thought of siblings as interchangeable parts, as mere playmates. One of the things they began realizing is that parents are like doctors on grand rounds in a hospital; siblings are like nurses on the ward — so siblings really know you better than your parents.

Q. Given all the emotional variables, isn't it hard to subject sibling relationships to scientific analysis?

A. Oh, yes. One of the things one of the researchers said to me was that it was just too much of a muddle — people didn't know how to tease out all the threads. But that dam began breaking 15 or 20 years ago. Now, we can begin to start seeing the results of longitudinal studies.

Q. How has recent research altered conventional wisdom about siblings?

A. We're learning how important it is both to preserve sibling relationships if they work and repair them if they're broken. We're also learning a lot about nonliteral siblings — stepsiblings, half-siblings — and the surprising power they can have. Most research shows that in blended homes, if a family can stay together for about six years, the difference between two stepsiblings or two full siblings is often really nonexistent.

Next: Are older children generally closer to parents? >>

Q. What has most surprised you?

A. A few things about fighting were surprising to me: The most physically aggressive of all sibling relationships is not, as you would think, the boy-boy relationship. It's actually the boy-girl relationship — usually the younger brother directed at the older sister. The most damaging of all kinds of fighting between siblings is usually the girl-girl emotional interplay. Girls tend to expose their emotional soft spots to each other more than boys do, and when you do that, you're much more open to the cutting remark.

Q. How important is birth order in shaping personality and life outcomes?

A. There is a not inconsequential minority of researchers who analogize birth order to astrology — [they think] it's too simplistic. The majority think this is one area where the [conventional wisdom] got it right: It is generally true that the firstborn is more aggressive, more successful. The firstborn tend to have a three-point IQ advantage over the second-born. Twenty-one of the first 23 astronauts were firstborn or only children. Last-borns tend to be funnier, more empathic, more intuitive. They're much likelier to be rebels. Middle-borns do tend to be the ones who are stuck in the center seat for life. They tend to take longer to find themselves.

Q. Are older children generally closer to parents?

A. Parents are more invested in older children from the outset. And older children tend to repay that loyalty with greater loyalty to the family. Particularly with the girls, they tend to be the family archivists; they also are the likeliest to be the caretakers of the parents.

Q. Isn't gender the most powerful factor of all?

A. It is, but that's more societal than it is anything else. In terms of temperament and life arc, birth order tends to be a bigger factor than overall age, income, gender, even education.

Q. How did the dysfunction of your childhood home, with a violent father and drug-addicted mother, shape the relationships among you and your brothers?

A. There was almost a hostage situation: We felt like we were people drawn together by crisis and adversity. Those things cause a lot of stress cracks in relationships. Either those stress cracks turn into fractures and relationships break apart, or they have a certain annealing power, and you develop bonds that seem all but unbreakable.

Next: What is the value of sibling relationships in adulthood? >>

Q. In your case, you stayed close.

A. We do remain very close. And that's not to say it's remotely ideal. But the relationships remain extraordinarily powerful.

Q. What have you learned from your interactions with your half-siblings and stepsiblings?

A. My stepsiblings were an unfortunate aberration. The relationship was so deeply dysfunctional between the two parents [Kluger's mother and his stepfather] and the time we all had in each other's company was so brief. When their marriage ended, after 15 months, our relationships with those kids pretty much ended. One of the unfortunate things I learned is that those stepsibling relationships are so easily destructible — and what a waste that was.

Q. But your relationships with your father's son and daughter from his second marriage turned out better.

A. We overcame so much adversity. I didn't really know them at all till they were in their mid-20s and I was in my mid-30s. We were so hostile to their mother; she was so hostile to us; we were so deeply resentful that they had gotten a reasonably good upbringing from our father. All of that spelled almost certain hopelessness for those relationships. And the fact that we made so much of the relationships since then — that was entirely improbable. The real love that's developed in 20 years has really taken us by surprise.

Q. What is the value of sibling relationships in adulthood?

A. Siblings can be sources of real physical and mental health for one another in ways that we didn't always fully appreciate. We all thrive more when we're part of a supportive social network, when there's somebody double-checking on us, making us accountable. We also stay more alert emotionally. All of these things are making siblings more valuable to each other as life spans extend.

Q. Yet stresses also arise over issues such as aging parents and inheritance. Do you have any advice in these areas?

A. When it comes to caring for aging parents, to the degree you can do it, the best approach is what's in the best interest of the parents. In terms of inheritance, the gold standard is, what will it take to make everybody feel reasonably whole?

Q. What messages would you like readers to take from the book?

A. There are two things. Siblings are not the sine qua non of a happy life. But having siblings and not making the most of them is like having 1,000 acres of incredibly fertile farm land and never planting a single seed.

Q. The other?

A. Never assume your relationship is irreparable because, first of all, your life circumstances may change. Or [a relationship may improve] simply because you make an effort. The power of a sibling who knows everything about you, who knows the family you grew up in, who carries half your genes — there's nothing quite like that.

Julia M. Klein is a cultural reporter and critic in Philadelphia and a contributing editor at Columbia Journalism Review.