The problem of excess siblings…

Thursday, February 15, 2024.

Having more siblings is linked to worse mental health, an extensive analysis of children in both China and the United States has revealed.

The negative impact is highest with closely spaced siblings since it intensifies competition.

The reason may be that more siblings mean each one gets less attention and resources, and this damages mental health.

The quality and duration of parental attention and family resources matter.

This research reveals how too many siblings can impact your mental health.

Professor Doug Downey, the study’s first author, said:

“Our results couldn’t have been easily predicted before we did the study.

Other studies have shown that having more siblings is associated with some positive effects, so our results were not a given.”

How the study was conducted

The study drew on data from over 9,400 Chinese and 9,100 American eighth graders. I love that this was a multicultural study of the two leading economies.

In both nations, adolescents (their average age was 14) were surveyed about their mental health.

Interestingly, the Chinese had an average of 0.7 fewer siblings than their American counterparts, reflecting the notorious One Child Policy’s impact.

Chinese findings suggested that only children had the best overall mental health, while in the U.S., those with no or only one sibling displayed similar mental health scores.

In the U.S., both half-siblings and full-siblings were linked to having poorer mental health, mainly when siblings were older and closely spaced.

Siblings born within one year of each other had, on average, the worst mental health. This was a fascinating and essential finding.

One theoretical explanation is down to a sort of ‘resource depletion’ Professor Downey elaborated:

“If you think of parental resources like a pie, one child means that they get all the pie—all the attention and resources of the parents.

But when you add more siblings, each child gets fewer resources and attention from the parents, and that may have an impact on their mental health.”

The sibling influence does enhance social skills, however…

Despite these negative findings, having more siblings does have an upside.

For example, research suggests that having more siblings correlates with better social skills measured in kindergarteners and, strangely enough, future lower adult divorce rates.

However, at the end of the day, these findings are fairly negative. Professor Downey explained:

“What we found is that when you add all the evidence up, the effect of siblings on mental health is more on the negative side than the positive side.”

Professor Downey noted that the results come amid decreasing fertility rates globally:

“This combination of results is not easily explained.

We still have more to learn about the impact of siblings.

This is particularly important now as the U.S. and other countries have lower fertility rates.

Understanding the consequences of growing up with fewer or no brothers and sisters is an increasingly important social issue.”

Final thoughts

He’s right. The media is avoiding the topic, but we’ll soon be experiencing population declines of significant import.

Perhaps another way of looking at it is that the benefit of siblings is to provide developmental boosts through competition for resources.

Nature builds in a buffer to allow a sibling's Positive Sentiment Override to function in less-than-perfect situations. We can’t all be special snowflakes; few aspire to be.

Be well, stay kind, and Godspeed.

REFERENCES:

Downey, D. B., & Cao, R. (2023). Number of Siblings and Mental Health Among Adolescents: Evidence From the U.S. and China. Journal of Family Issues, 0(0). https://doi.org/10.1177/0192513X231220045