Only children do not have the best reputation. Researchers, journalists, and ordinary people alike have described people who grow up without siblings as egocentric, selfish, anxious, and socially inept. The assumption is that, because only children do not have to share parents’ attention and have no opportunity to practice their social skills with brothers or sisters, they grow up to be self-centered and even “narcissistic.” The famous American psychologist, G. Stanley Hall, even went so far as to state that “being an only child is a disease in itself.” Ouch!

But is that true? Do people who grew up as only children actually have elevated narcissism scores? My colleagues and I addressed this question in two studies.

First, we wanted to confirm that ordinary people do, in fact, generally think that only children are more narcissistic. So, we asked a sample of several hundred respondents of varying ages and from different demographic backgrounds to rate the average person who grew up as an only child and the average person who grew up with siblings in terms of narcissism. As we expected, participants rated the typical only child as more narcissistic than the typical person with siblings. Interestingly, this tendency was more pronounced among participants who had siblings. The findings showed that the stereotype of the narcissistic only child is alive-and-well—and that it is especially strong among people who are not only children themselves.

In the second study, we analyzed data from a sample of nearly 2000 respondents that was representative of the German population to test whether only children and people with siblings actually differ in their level of narcissism. Contrary to the stereotype, we found no significant difference in narcissism between the two groups. We investigated subcomponents of narcissism separately in case only children were higher in only some aspects of narcissism, and we also tested the possibility that extraneous variables may be obscuring differences in narcissism between the groups. Yet, we still failed to find a difference between people who did and did not have siblings.  Clearly, our results did not confirm the stereotype.

In combination, the findings of the two studies indicate that, although people believe that only children are more narcissistic than people with siblings, this believe is false. These results align well with a good deal of other research indicating that only children and non-only children are highly similar in their personalities.

So, it’s clearly time to set the stereotype that only children are particularly narcissistic aside. When sociologists, economists, and policy makers discuss the downsides of low fertility rates, they should let go of the idea that growing up without siblings leads to increased narcissism.   

For Further Reading

Duffner, M., Back, M. D., Oehme, F. F., & Schmukle, S. C. (2020). The End of a Stereotype: Only Children Are Not More Narcissistic Than People With Siblings. Social Psychological and Personality Science, 11, 416-424.

Michael Duffner is a professor of personality psychology and psychological assessment at the Witten/Herdecke University. His research primarily deals with the antecedents and consequences of self-enhancement.