A New Study Challenges the Stereotype That Children Who Grow Up Without Siblings Are More Narcissistic

You've may heard people say that only children are more self-centered than those with siblings, but is that actually true? Researchers at the University of Leipzig and University of Münster set out to find a conclusive answer. Their findings? While it's true that being an only child can correlate to narcissism, the research team found that there are other traits that can make someone conceited, too.

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The study, "The End of a Stereotype: Only Children Are Not More Narcissistic Than People With Siblings," published in Sage Journals, stated that narcissism first begins with the genes that people inherit. According to the researchers' analysis, genes make up 50 percent of people's aptitude to become narcissistic. Parenting also plays a large role in the traits children develop. The university researchers touched on the fact that parents who are highly critical or have strict expectations of their children tend to contribute to their development of self-absorbed traits. "The basic assumption is that children internalize their parents' praise and expectations and develop narcissistic features such as feelings of grandiosity and entitlement," the study said.

Related: Study Suggests That Having a Sister Could Actually Be Good for Your Mental Health

The researchers first collected data about public opinion of only children in the form of an online questionnaire, which asked participants to weigh in on whether or not they thought people without siblings were more self-centered than those who do have brothers and sisters. The responses they received showed that most people feel only children are the more narcissistic group. However, data from a panel also conducted by the researchers confirmed that the stereotype was untrue. They found that narcissistic traits did not directly correlate to only children, regardless of age, sex, socioeconomic status, place of residence during childhood, parental presence, or migration background.

This study took place solely in Germany and exclusively went over "grandiose narcissism" rather than other forms of narcissism. All that being said, the study does still prompt the idea that narcissism is not strictly correlated with children who grew up without siblings. "This research suggests that the belief that only children are higher in grandiose narcissism than non-only children is widespread but inaccurate," the study said.