The debate has raged for more than a century: Does birth order help shape personality, or are conscientious firstborns and creative youngest children flawed stereotypes based on weak evidence?
After decades of disputed claims, a handful recent studies found that there was little evidence for meaningful differences. But in a study published on Monday, psychologists have pushed back and claimed it does have an effect after all.
In one of the largest studies ever conducted on birth order, family size and personality, Canadian researchers collected data from more than 700,000 volunteers and found that, on average, middle children outperformed their Scored higher marks than siblings.
Scores for the same traits were also higher in families with more children, suggesting that people may be more likely to develop a cooperative personality when they grow up as part of a larger group.
The effects aren’t large, but Michael Ashton and Kibeom Lee, psychology professors at Brock University in Ontario and the University of Calgary in Alberta, respectively, believe they challenge the idea that birth order and the number of children raised together have a significant impact. There is no significant effect on personality. ,
“The weight of that evidence now indicates that personality trait levels vary depending on birth order and sibling size,” they write. Proceedings of the National Academy of Sciences,
Researchers have speculated on the impact of birth order for more than a century. In 1874, polymath Francis Galton, the youngest of nine siblings, gathered the history of a group of English scientists and made a discovery. there were a large number of firstborn childrenHe suspected that the eldest received more attention from their parents, leading them to reach greater intellectual heights.
Decades later, Austrian psychologist Alfred Adler claimed that first-born children are often dutiful and responsible, while youngest children can be independent and creative as they look for ways to stand out. Middle children she saw as peacemakers, although others considered them “forgotten children”: Lisa Simpson who are often ignored.
Ashton and Lee analyzed personality traits reported by more than 700,000 English speakers, who also detailed whether they were a first-born sibling, middle child, youngest, or only child. A separate group of 75,000 volunteers completed the same questions, along with the number of children they had fostered with them.
Previous studies have found evidence that first-born babies are slightly smarter than late-born babies, and this was also seen in a Canadian study. But the researchers also noticed other differences. People with more siblings score higher on two traits associated with cooperation, namely agreeableness and what scientists call honesty-humility, or the tendency to be fair and genuine with others. Middle children appeared to get more of a boost, scoring slightly higher than first-borns and youngest siblings.
The findings show that if an only child and a single person are randomly selected from a family of six, there is a 60% chance that the person from the family of six will be the more agreeable one. “You can’t tell much about a person’s personality from their birth order or family size, even though there are obvious differences when averaged across many people,” Lee said.
While the number of siblings was the main factor shaping personality traits, birth order also mattered. “These differences were primarily due to sibling size effects,” Ashton said. “However, birth order differences cannot be explained solely by sibling size, which indicates that birth order has a small effect on cooperative personality traits, even for middle and youngest children. The average is slightly higher than that of the oldest.”
If the effects are real, some drivers may be intuitive, the authors write: that having more siblings promotes a more cooperative personality, while being the middle child may lead to good bonds with younger and older siblings. Is required.