Research shows first born children garner most success

( -- The order in which children are born influences their personality and success, according to decades of research. Forty-three percent of the country's CEO's, more than half of U.S. presidents and 21 out of 23 astronauts were all first born children.

Joshua Hartshorne, post-doctorate fellow in the department of brain and cognitive sciences at MIT says a lot of it boils down to parenting. First born children command all of their parents' attention before another sibling is born. First born children turn into adults that take charge, are motivated to achieve and according to a survey, make an average of $100,000 or more per year than younger siblings.

Fox 25's Sara Underwood interviewed Amanda and Jim Liljedahl, parents to five children.

When asked if their children had different personalities, Amanda said they were all unique.

"I would say yes they are all different even the twins each their own personalities," she said. "It's really interesting to see how they've each kind of developed and how having siblings has developed their personalities."

First born Jameson is very responsible and an achiever, according to his parents.

Middle children tend to be people pleasers who look for identity among their peers, which may be why they are somewhat rebellious, according to researchers.

Cameron, who is a middle child in the Liljedahl family, uses his personality to be outgoing so he doesn't get lost in the middle, his parents said. Middle children tend to earn an average of $35,000 less per year than older siblings.

The last born child is typically carefree and spoiled, according to some experts. By the time parents have their last child, they can be more lenient. Last born children feel the need to prove themselves to their older siblings, but are still the least likely to earn a six-figure income.

Only children are considered "super first borns," and they tend to possess characteristics similar to a first born child.

Research also shows that no matter where you fall in your birth order, the size of your family, age gaps and overall childhood experiences shape your personality.