What Sibling Spacing and Birth Order Says About Baby No. 2

— -- Royal watchers got their wish: The Duchess of Cambridge is pregnant again.

Little is known about royal baby no. 2 so far, except that he or she's already giving Kate severe morning sickness.

But we do know that this baby will be a second-born -- and with that generally comes with personality that differ from first-borns. A recent study from Feifei Bu of the Institute for Social and Economic Research at the Britain's University of Essex found that first-borns are more ambitious and also more advantaged when it comes to education.

READ: Princes William, Harry React to Royal Baby News

Photos: Royal Baby Revealed in Family Photos

It's unlikely that this second-born will have to make many sacrifices for it's older sibling, save perhaps the throne. But things are about to change for Price George.

"As the first child gets older, things change for the family, as well," said Linda Murray, BabyCenter’s Global Editor in Chief. "Moms and dads become more confident in their parenting and more equally share the caregiving. And parents begin rediscovering each other and focusing on their relationship, now that the child is more independent, which is often how the second child comes along."

Though Buckingham Palace confirmed that Kate is not yet 12 weeks pregnant, if she is close to the three-month mark, then the babies will be about 21 months apart in age. It's a popular age-gap for parents. A recent, non-scientific poll on BabyCentre.co.uk found nearly 70 percent of respondents said an 18-month to three-year age gap the "best."

Experts say the age gap could mean royal baby #2 might have a bit of a wild streak.

Richard Gilham, BabyCentre child psychologist wrote, "Like wild-children Harry and Pippa, the new Royal baby will also be around two years younger than Prince George. It's quite possible that like their uncle and aunt, the young Prince or Princess may well turn out to be a little wilder than Kate and Wills."