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What Happens to an Only Child When Their Parents Divorce?

2026-09-11

This site’s two original 2008 pieces on divorce were written from experience and empathy, not research citations. Twenty years later, here’s what the actual literature says about whether, and how, going through it alone, without a sibling in the house, makes a real difference.

What our own poll can (and can’t) tell us here

Worth flagging honestly up front: this site’s 2026 reader poll asked parents about broad fears like loneliness, eldercare, and social skills, but divorce wasn’t one of the listed options, so we don’t have a direct percentage to compare against here the way some of this site’s other new research pieces can. What we do have is twenty years of real reader testimony sitting in Divorce and the Only Child and Easing the Impact of a Messy Divorce, which the research below can now sit alongside.

Siblings help, but only when things are genuinely bad

An older but still frequently-cited study in the American Journal of Orthopsychiatry looked at university students who’d grown up in either high-conflict or low-conflict homes, comparing psychological adjustment by how much sibling support they’d had growing up.

In high-conflict households, students with strong sibling support showed meaningfully better adjustment than both only children and students with weak sibling support. In low-conflict households, sibling support made no measurable difference at all (Caya & Liem, 1998).

That’s a specific, useful finding: the protective effect of a sibling isn’t about having someone to play with. It’s about having someone else living through the same conflict who understands exactly what it’s like, a kind of support that’s hard to fully replace, and that only becomes relevant once conflict is actually high. In a low-conflict separation, the research suggests an only child isn’t at any particular disadvantage.

A newer, longitudinal look

A 2022 study in the Journal of Marriage and Family tracked sibling-relationship quality over time as a predictor of how children adjusted after a parental divorce, not just a single snapshot, but a trajectory (Dijk et al., 2022). We haven’t been able to pull the exact figures from this one yet, but its existence matters: this is still an active area of research, not a settled question from the 1990s.

A word of caution about one small study

A 2022 Baylor University honors thesis is worth mentioning because it’s genuinely the most specific attempt we found to measure sibling-count effects on adult outcomes after childhood divorce specifically, but it’s worth being just as clear about its limits. It was a secondary re-analysis of data collected for an unrelated study, with only 35 divorced-parent participants split across several sub-groups. One notable wrinkle from that small sample: children under 12 at the time of divorce with three or more siblings actually scored higher on rule-breaking behavior than those with one or two, a reminder that “more siblings equals more protection” isn’t a straight line, even if it holds up on average (Potts, 2022). Treat this one as a lead worth following up on, not conclusive evidence.

The honest summary

The clearest, best-supported finding here is narrow but real: siblings are protective specifically in high-conflict divorces, not divorce in general. If your own separation was or is high-conflict and your child is an only child, that’s the situation where deliberately building outside support, extended family, close friends, a counselor, matters most. If it wasn’t high-conflict, the research doesn’t suggest your child is worse off for being an only child.

Sources cited:

  • Caya & Liem (1998), “The Role of Sibling Support in High-Conflict Families,” American Journal of Orthopsychiatry, 68(2), 327–333, note: findings from secondary summaries, not an independently re-verified read of the original abstract
  • Dijk, Deutz, Bakermans-Kranenburg et al. (2022), “Longitudinal Associations Between Sibling Relationship Quality and Child Adjustment After Divorce,” Journal of Marriage and Family
  • Potts (2022), Baylor University honors thesis, “Siblings Improve Adult Psychosocial Health of Individuals Who Experienced Parental Divorce in Childhood”, undergraduate thesis, small sample, treat as exploratory