How Siblings Shape Us

Happy Mother’s Day. The cover story in today’s Times Magazine begins with an idea: While parents work hard to mold their offspring, those offspring just as often mold each other. Susan Dominus, who has written many moving pieces about children and families, looks at a growing field of research to see how kids’ personalities “spill over” onto their siblings. It’s not always the way you’d think.

As the father of three boys (and as a sibling myself), I was rapt. You should read the story. In today’s newsletter, I ask Susan a few questions about her findings.

What got you interested in this story?

My older brother was extremely influential in my own life. When I was 14, and he was home on a break from college, he talked me into starting a school newspaper. He somehow knew before I did (and definitely before my parents did) what kind of work I would love doing. When I started interviewing people about the way their families influenced their lives, I was struck by how often siblings played a pivotal role in their careers — in making an introduction, giving a key piece of advice, setting the bar high.

You tell the story of several high-achieving families. But the phenomenon isn’t necessarily strongest among the privileged, is it?

Not at all. If anything, research suggests that what’s known as the “sibling spillover effect” (a measure of how much siblings influence each other, especially academically) is more powerful in disadvantaged families. In those families, the bond can be more influential — the siblings spend a lot of time together, either because their parents are so busy working, or because the family doesn’t have the resources to spend on tons of extracurriculars.

My kids have wildly different personalities. Tell me what the research shows about birth-order psychology — the idea that your place among siblings shapes you?