Can your birthday affect your personality?

Telling someone when you were born can sometimes feel like revealing a part of your personality.

In popular culture it is not unusual to hear discussions about star signs and how they may go on to influence your overall character, compatibility with others or careers.

While astrology has existed for thousands of years, science has long ruled out its credibility. But there have been a number of scientific studies which explore whether your birth month or season can impact your life later down the line.

What does science say about the link between personality and birth months?

Scientific studies exploring the relationship between birth months and personality traits can be traced back to at least the 1970s.

Some researchers have debunked the connection, stating that a person’s character is shaped by the things they experience in life. Others have published findings which suggest that birth months or seasons may have an impact.

In 2013 the Journal of Social Sciences published a paper that identified a link between birth months and the likelihood of becoming a celebrity.

By using a small sample of 300 famous people, ranging from politicians and sports people to actors and musicians, researchers found that the highest number of celebrities were born under the Aquarius sign - between late January into mid-February.

Is fame written in the stars?..Not quite

The study caused much discussion amongst social scientists, including Dr Mark Hamilton, a Professor of Communication at the University of Connecticut, who spoke to BBC Bitesize.

Along with a team of researchers, he worked on a much larger sample of 85,000 celebrities and notable figures, dating back as far as 3000 BC right up to the modern day.

“We ran the same data analysis on those individuals and it supported the same patterns that we saw with [the original] finding,” he told us.

So what could this mean?

Dr Hamilton believes the answer may be found in a field of science called chronobiology, which refers to the study of rhythms or cycles in living things.

This means that factors such as climate and sunlight exposure at the time of your birth could potentially impact you throughout your life.

“Chronobiology is a relatively new area,” Dr Hamilton said.

“We’re finding that the things that happen early on [in life], even prenatal, can have an impact on what happens to you later on.”

While astrology isn’t an indicator of success, there are aspects of it which can serve as a reminder of chronobiological timings and patterns of nature, Dr Hamilton explains.

How does your age at school affect your personality?

In further research, Dr Hamilton found that the birth month of school children in the same year group could have an impact on the likelihood of becoming a celebrity.

He highlights that when comparing your results with others in class, whether that be in physical activities or in tests, it’s important to remember that your peers could have a relative advantage. This means that someone born at the start of the school year might perform slightly better than those born towards the end of the school year - with some children almost a year older than others.

What starts out as a relative advantage may then go on to affect your personality - with early successes in school possibly providing a higher self-confidence into adulthood.

“When I was younger I would look at these kids and think, how do you do that? And the answer is because they are older.” Dr Hamilton told us.

“There’s all sorts of evidence now, from hockey to football, that if you happen to be older in your class - you tend to be the person who becomes the professional player. It’s really surprising.”

But these findings aren't fixed in determining someone's fate. Dr Hamilton highlights that these comparative advantages tend to diminish over time.

What have other studies looked at?

In 2014 the European College of Neuropsychopharmacology published research that suggested the season you are born in could have a significant impact on your mood.

They identified a trend that those born in spring and summer were more likely to have a hyperthymic temperament - meaning they have a tendency to be excessively positive.

It also found that people born in the winter months were significantly less prone to irritable temperaments than those born at other times of the year.

What’s more, other studies have suggested that you may be more likely to pick up certain hobbies or careers in different birth months.

In 2016, the National Football Museum published research looked at the birthdays of the inductees to their Hall of Fame from over the years, and found that the majority of these successful players were born between September and December - almost double those born between January and April.

But if you fancy a career in the beautiful game and weren’t born between September and December, fear not: footballing legends like Cristiano Ronaldo, who was born in February, and Lionel Messi, born in June, are just two of the many exceptions to this.

If football isn't the game for you, then maybe chess might be. In a 2008 study conducted at Brunel University, researchers found that there was a relationship between seasonal patterns and the population of expert chess players in the Northern Hemisphere. Data suggested that a significant number of these players were born in late winter and early spring. Checkmate!

The same research paper also highlights that the prevalence of left-handedness is higher amongst chess players than in the general population.

This article was published in September 2024