People born during the summer months are the least likely to become chief executive officers, a study has found.
Researchers at the University of British Columbia looked at 375 CEOs in the S&P 500 companies between 1992 and 2009.
In the US, school cut-off dates mean the youngest students are born in June and July, while the oldest are born in March and April.
The study found that just 6.13 CEOs were born in June, and 5.87 were July babies. In comparison, 12.53 and 10.67 were born in March and April respectively.
Professor Maurice Levi, from the university's Sauder School of Business, said: "Our findings indicate that summer babies underperform in the ranks of CEOs as a result of the 'birth-date effect'."
The UK has a similar system in terms of school groupings, with the youngest born in June, July and August.
Levi said: "Older children within the same grade tend to do better than the youngest, who are less intellectually developed.
"Early success is often rewarded with leadership roles and enriched learning opportunities, leading to future advantages that are magnified throughout life.
"Our study adds to the growing evidence that the way our education system groups students by age impacts their lifelong success.
"We could be excluding some of the business world's best talent simply by enrolling them in school too early."
However, Megan Pacey, chief executive of Early Education, said that while the study raises valuable points, she said providing pre-school education that is "developmentally appropriate" is extremely important.
She told IB Times UK: "This American research highlights a long-standing concern around summer born children which will be familiar to many teachers and parents.
"Understanding and responding to challenges raised in this report however, is a complex task and requires looking beyond the simple fact of a child's date of birth. "
"Focusing on the child's date of birth risks missing what is really important. Early years education provision, wherever it takes place, should be developmentally appropriate and should lay solid foundations for the kind of learning that is required later for the more formal curriculum and learning that will follow."