New research shows how a child’s birth date influences how well they do in school, and later in life.
The research was published in The Conversation by Lionel Page, Dipanwita Sarkar and Juliana Silva Goncalves from the Queensland University of Technology (QUT).
“Our new research shows your birthday month may also contribute to shaping your personality. In particular, we found people’s self-confidence can significantly differ because of their month of birth,” they wrote.
The reason, they say, isn’t one’s astrological sign, but rather the role that person’s birth date plays in deciding when they enter school.
“Most countries specify when young children should start school using a cut-off date in the year. For instance, in the UK the cut-off date is September 1. In federal nations such as Australia or the US, cut-off dates vary between states,” the researchers explain.
“Children who turn five by the cut-off date will start school, while children whose birthday is after the cut-off date will still be four and start school the following year.”
They point out that the relative position of a person’s birthday to the school cut-off date has one important consequence: it determines whether throughout primary and secondary school they are among the older, more mature, taller students in the class or not.
A large body of research has shown that students who were relatively old among their peers are more likely to become professional sports players.
This pattern, the researchers of the latest study say, is evident across a wide range of sports in many different countries with different cut-off dates: soccer, ice hockey and AFL.
Famous footballers who were relatively old among their peers include for instance Pep Guardiola, the current manager of Manchester City.
Studies have also found relatively old students do better at school. Even though the advantage tends to decrease over time, they are still slightly more likely to go to university.
The role of self-confidence
The research suggests one of the main reasons for this “birthday effect” is the impact of relative age on self-confidence.
“Recent research shows children who enjoy being ranked relatively high compared to their peers have higher self-confidence. Being relatively old among your peers tends to place you higher in the distribution of achievement,” the researchers wrote.
“Children who enjoy this throughout childhood can end up being more confident in their aptitude and carry this confidence with them later on.”
To test this idea, the researchers conducted two studies: the first was with Australian school children in Years 8-9 (13- to 15-year-olds), who were born one month apart from the school cut-off date.
“We surveyed 661 children about their tendency to take risks and to feel confident. We found evidence some of the relatively old boys tended to be more competitive than their peers,” the researchers explained.
In the second study, the researchers surveyed more than 1,000 Australian adults (24- to 60-year-olds) who were born on different sides of the cut-off date in their state.
“We found those who had been relatively old at school were more confident in their ability in a task involving simple mathematical calculations,” the researchers wrote.
“They also indicated they were more willing to take risks in their lives than those who had been relatively young.”
The original article, which appeared in The Conversation, has been edited for length.