Benefits of Siblings

Children born under China’s One-Child Policy exhibit more negative personality traits in adulthood than those born prior.

By Ruth Williams | January 10, 2013

WIKIMEDIA, BrokenSphereSiblings sometimes squabble, but they might also be helping each other become more trustworthy, conscientious, and optimistic individuals, according to a report published today (Jan 10) in Science. The study, which looked at people born in Beijing just prior to or just after the introduction of the One-Child Policy, reveals a number of personality differences in adulthood most likely attributable to the presence or absence of siblings.

“They’ve identified this opportunity to establish a causal relationship between being a single child and how one behaves,” said Abigail Barr, a professor of economics at the University of Nottingham in the United Kingdom, who was not involved in the study. “And they’ve used lab-type experiments to do the measurements. It’s really good science.”

The One-Child Policy, introduced in 1979, is a unique natural experiment, said Lisa Cameron, a professor of econometrics and business statistics at Monash University in Melbourne, Australia, who led the study. But it’s also politically controversial. “In China, there is concern about the One-Child Policy generation,” said Cameron. “There have been calls for the abolition of the policy on the basis of [that generation having] poor social skills, but there’s been no research documenting whether it has actually had an impact on people.”

Most research seems to suggest few if any personality effects of being an only child. “Studies done in other countries have found that only children are very much like other children,” said Susan Newman, a social psychologist and author of The Case for The Only Child. “You have hundreds of studies that actually contradict the findings here.” Indeed, even previous studies of only children in China found them to be largely similar to kids with siblings.

However, said Cameron, “If you just compare only children with others, what you end up identifying is the effect of being an only child plus the effect of family background.” That is, parents who choose to have an only child may differ from those who chose to have many, be it in their parenting style, personality, genetics, or other attributes. “You can’t get a clean measure of what it means to be an only child,” she said.

Because the One-Child Policy removes parents’ choice, it eliminates the family-background variable, Cameron explained, so “we can isolate the effect of being an only child.”

The team also controlled for cultural background and, as closely as possible, for age, recruiting people who were born in Beijing no more than 5 years before or after the policy’s introduction and who grew up in the city.

The team had the participants play simple economics games, which involve the exchange of money between anonymous participants and are designed to test a range of personality indicators. The games revealed that people born after the introduction of the policy were, not only less trusting, less trustworthy, and more pessimistic, but also less competitive, less conscientious, and more risk-averse.

Previous studies of only children have relied on inherently weak measures like questionnaires and observations of children’s behavior to garner data. “When there’s money on the table, you are much more likely to identify [a person’s] preferences and their real behavioral tendencies than if you ask them a hypothetical question,” said Barr. These methodological differences may explain why Cameron and colleagues see an only child effect that previous studies have not, she added.

The findings offer support to those campaigning for the abolition of the One-Child Policy, said Barr, and may have implications for only children outside of China. “It doesn’t give us a definitive answer regarding only children in other contexts, but it does change the default position,” she said. “Instead of saying, well, the best guess is there’s no difference [between singletons and non-singletons], I think it does shift us towards, well, there could be.”

At this stage, perhaps it is best to steer clear of generalizations. Newman is particularly wary. “It just adds to the stereotyping of only children . . . and the stigma that surrounds them,” she said.

Barr disagreed. “If [the new findings] get a debate going about the way children are brought up, I don’t think it will be a bad thing.”


L. Cameron et al., “Little Emperors: Behavioral Impacts of China’s One-Child Policy,” Science, doi: 10.1126/science.1230221, 2013.

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Avatar of: Baxter Zappa

Baxter Zappa

Posts: 11

January 12, 2013

I did not read the original study, but if it is as described, the study sounds highly flawed. I would think that the fact that the only child group used here was raised primarily by parents who wanted to have more than one child but were stuck with having only one or suffering legal/social/economic consequences is highly significant, but this was not controlled for.
Avatar of: PD


Posts: 18

January 14, 2013

The personalitiy difference of those Chinese born during China's One-Child policy is minor compared to other problems it has caused. 

Forced abortions on those mothers who refuse to follow the law is reprehensible.  Apparently, there are speical police who find those offenders and force them to have abortions.  One recent story explains how the aborted baby was put next to the mother as she was recovering from the abortion to "encourage" her not to get pregnant again.

Sex-selection abortions are a major problem in China.  The one-child policy has caused unnatural higher percentages of male babies born to families due to preferences for a male child.  Over time, this has caused more bachelors in China which fuels a pornography epidemic, prostitution and sex-trafficking. 

China's one-child policy is a social experiment gone bad and the US needs to be more aware of what is going on in China and encourage them to stop it.

Avatar of: GerryS


Posts: 37

January 14, 2013

I guess the term used in China "emperor generation" has gained a little more meaning from this information, but not all single kids are self-absorbed.

I am from a large family with personalities of a wide range.  Our parents are very loving and God-fearing people.  The love fostered among us by them seems to have overcome the worst of our major trials and squabbles.  There is a built-in socializing, support system that serves well to prepare us for some of the complex human interactions we encounter in the world.  I only wish we were prepared for some of the disgusting self-absorbed antisocial behaviors we have had to encounter by people whose only skills seem to have been to use others for their own self-gain and pleasures.  That was our big difference.  We had our family ways of crushing a lot of that kind of behavior.  Not that it was not there, but we had a built-in set of checks and balances that I do not know how can be quantified by science without intruding in on the natural realm, our own built-in iron to sharpen iron.

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