What science is seeing

Research Findings

The grief that follows a sibling's death has measurable shadows — in the body, in the years that follow, and across the lines of race and inequity.

  1. 80%

    of Americans

    grow up in a household with a sibling.

    Source

    U.S. Census (2023). National Siblings Day. census.gov/newsroom/stories/siblings.html

  2. Lifelong

    the longest tie

    Sibling relationships are the longest family tie across the lifespan.

    Source

    Gilligan, M., Stocker, C. M., & Jewsbury Conger, K. (2020). Sibling relationships in adulthood: Research findings and new frontiers. Journal of Family Theory & Review, 12(3), 305–320.

  3. +30%

    fatal stroke risk

    Women have a 30% greater risk of fatal stroke following the loss of a sibling. There is also an increased risk of heart attack for women following sibling death from external causes such as accidents or suicide.

    Source

    Rostila, M., Saarela, J., & Kawachi, I. (2013). Fatal stroke after the death of a sibling: a nationwide follow-up study from Sweden. PloS one, 8(2), e56994.

  4. +50%

    by age 60

    By age 60, Black siblings are 50% more likely to have lost a brother or sister compared to Whites.

    Source

    Umberson, D., Olson, J. S., Crosnoe, R., Liu, H., Pudrovska, T., & Donnelly, R. (2017). Death of family members as an overlooked source of racial disadvantage in the United States. PNAS, 114(5), 915–920.

  5. +54%

    dementia risk

    Sibling loss in mid-to-late life is associated with an estimated 54% increased risk for dementia. The risk is greater for Black Americans, who experience increased instances of sibling loss across the life course.

    Source

    Cha, H., Thomas, P. A., & Umberson, D. (2022). Sibling deaths, racial/ethnic disadvantage, and dementia in later life. The Journals of Gerontology: Series B, 77(8), 1539–1549.

Grief inequity is one of the mechanisms by which structural disadvantage becomes biological.
After Umberson et al. (2017)
How to read these numbers

Sibling loss is a health event.

The cardiovascular and cognitive risks above are not coincidence. Bereavement reshapes sleep, immune function, and chronic disease trajectories. Treating sibling loss as preventive medicine is overdue.

The burden is unevenly distributed.

Black Americans lose siblings earlier and more often. Umberson's work names this 'an overlooked source of racial disadvantage' — grief inequity compounds across the life course.

The science is young.

Compared to research on parental and spousal bereavement, sibling-loss scholarship is decades behind. The numbers we have now are the floor, not the ceiling.