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The Sibling Effect Reader’s Guide

By Jeffrey Kluger

The Sibling Effect by Jeffrey Kluger


Questions and Topics for Discussion


Nobody affects us as deeply as our brothers and sisters do—not our parents, not our children, not our friends. Siblings are our collaborators and co–conspirators, our role models and cautionary tales. They teach us how to resolve conflicts and how not to, how to conduct friendships and when to walk away. Our siblings are the only people we know who truly qualify as partners for life.

In this groundbreaking book, renowned science writer Jeffrey Kluger explores—with insight and humor—the complex world of siblings in ways that are equal parts science, psychology, sociology, and memoir. Based heavily on new and emerging research, The Sibling Effect examines birth order, twin studies, genetic encoding of behavioral traits, emotional disorders and their effects on—and effects from—sibling relationships, and much more.



Jeffrey Kluger is a senior editor and writer at Time magazine. He is a co–author of the bestseller Apollo 13, and the author of Simplexity, Splendid Solution, Moon Hunters, and two novels for young adults. He lives in New York City.

  • “Our brothers and sisters are with us for the whole journey.” What are the benefits of having someone in your life to share so many of the highs and lows—someone who is not a parent or spouse? Are there any negatives?
  • “Parents inevitably wind up playing favorites, and kids, cleverly, learn to game their parents.” Do you find this to be true in your situation? In what ways did (do) you “game” your parents, and how have you been “gamed”? Did your parents play favorites or define a role for you? What was it?
  • Did the author’s use of examples from his own sibling relationship history help to humanize the scientific insights shared? How so?
  • “Four was about the age at which a child was fully weaned and no longer needed the resource of mom in order to eat. When you’re not competing with your baby sibling you’re less likely to try to hurt it.” Would you agree that this is true? Is four years between siblings the magic number?

  • The author looks to define the roots of conflict among siblings and finds that “close behind property as a trigger for sibling war making is the general concept of fairness.” What were some of the roots for the conflict you experienced with your siblings?

  • Were you the product of “alloparenting” by older siblings, relatives, or close friends? What was this experience like? What experiences did you come away with that you might not otherwise have had with a more “Western” style upbringing?

  • Were you familiar with birth order theory, or even stereotypes, before picking up this book? Which do you question, or think there might be validity to, after reading The Sibling Effect? Do any stereotypes like the firstborn “kin keeper” hold true?

  • What high and low power strategies, like using humor or keeping the status quo, have you seen siblings use to define themselves within a family?

  • What practical parenting advice could one take from this book? For example, being mindful of alliances and keeping the conversation healthy during a divorce, or relocating entirely when merging stepfamilies to keep the territory (and attitudes) neutral.

  • What is the cultural perception of singletons? Should we feel bad for them? Are they lacking in any key experiences, or are there benefits or unexpected perks? What stereotypes are they up against?

  • There are many pleasant benefits associated with twin life, including longer life expectancy and deeper social connectivity. Can you think of any others? If you’re a twin, have you ever experienced the “mind meld”?

  • What do you consider “the sibling effect” to be? In what ways have your early experiences with siblings—or life as a twin or singleton—shaped you?

  • Why did you pick up this book? Did you purchase it for a sibling? Has reading it caused you to look at your relationships any differently, perhaps in a more scientific light? What were the results?

  • How do you think sisters teach brothers about women and how do brothers teach sisters about men? Have you had that experience? If so, what did you find most helpful?

  • What will be some of the repercussions for countries with policies or beliefs that affect the gender balance, like China’s one–child–per–family policy and India’s favoritism for male offspring?
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