WASHINGTON – Firstborn children are more likely to go to the moon, according to a new study by CareerBuilder.

In fact, all seven of the original Mercury astronauts were firstborn.

The study says your birth order may determine how successful you are in life.

Michael Grose, author of “Why Firstborns Rule the World and Last Borns Want to Change It,” tells CNN.com “A child’s position in the family impacts his personality, his behavior, his learning and ultimately, his earning power.”

CareerBuilder says firstborns are more ambitious, assertive and dominant than their younger siblings and lean toward careers that require higher education such as medicine, engineering or law.

Oprah, Hilary Clinton, Winston Churchill and Bill Clinton are all firstborns.

Middle children are good negotiators and at making peace and compromises. They are more likely to identify with professional and technical staff level positions.

Famous middle children include David Letterman, Richard Nixon, Madonna and Princess Diana.

The youngest child loves the spotlight. They are charming, creative and have a good sense of humor and are not above manipulation. They are more likely to be found working in artisitc professions and outdoor jobs.

Famous youngest children include Jim Carrey, Billy Crystal, Steve Martin and Cameron Diaz.

To read more about what your birth position could say about you, follow this link.

WTOP’s Randi Martin contributed to this report. Follow @WTOP on Twitter.

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