For decades, researchers have linked birth order to personality traits. It's an extension of the age-old nature vs. nurture debate. It's hard to deny that our birth pedigree has some effect on our levels of intelligence, career choices, and ultimate success.

In interacting with and researching organizational leaders for many years, I've realized that birth order can be especially telling when it comes to assessing CEOs.

First Borns

For a time, first borns are the center of attention. Only at some later point - when a sibling shows up - do things start to go awry. First borns are "dethroned" from the spotlight and strive to regain parental attention. They develop a strong need to achieve.

Richard Branson is the epitome of a first born: "I love taking on the - you know, the status quo and trying to turn it upside down." Whether it's revolutionizing space travel or disrupting the airline industry, Branson doesn't let his ambition remain in check.

Consider also first-born Elon Musk. Musk has tackled the status quo through attempts to bring commercial space travel and electric vehicles to mass market. His advice? "[Do not] blindly follow trends. Question and challenge the status quo".

It turns out that first born females are even more ambitious than their male counterparts. Sheryl Sandberg is a textbook example. "Lean In" is a plug for her mantra that women should lean forward and ambitiously look for and seize opportunities.

If your CEO is a first born, chances are that he/she will be bent on tackling bold exciting feats and looking to disrupt existing industries.

Middle Borns

There's often a stigma associated with middle borns. Lacking the primacy of the first child, they tend to defer to the eldest's demands and don't develop the strong sense of ambition espoused by first borns. Suffice to say that while Elon Musk busies himself with colonizing Mars, his baby brother recently announced plans to open a fast-food restaurant.

Importantly, a lack of ambition isn't necessarily a bad thing. What middle children lack in ambition, they make up in terms of social prowess. Because they've grown up being the go-to mediator between their siblings, they develop strong social skills.

When middler Meg Whitman took the reins at HP, she decimated the barbed-wire fences in the parking lot (separating executives' vehicles from those of employees).

Like Whitman, middler Mark Zuckerberg strives to foster a collaborative workspace. Facebook offices have open floor plans. Zuckerberg explains, "[An open floor plan] facilitates people sharing and communicating about what they're doing, which enables better collaboration."

If your CEO is a middler, chances are you'll find yourself in a collaborative workspace working for a CEO who thrives in social situations.

Last Borns

Last borns are accustomed to getting their way. Not surprisingly, last borns tend to be partial to breaking rules. They're the most likely to rebel against authority.

Consider last born Rupert Murdoch. The media mogul has a reputation for living by his own rules. Murdoch recently waged a war against Google. Marching to the beat of his own drum, he's alleged plans to make News Corp sites invisible to Google's search engine. Conrad Black is another defiant last born. Not only has he been charged with eight counts of wire and mail fraud, he doesn't feel remorse for his actions, testifying "I have nothing to feel guilty or ashamed about from a moral imperative".

This isn't to say that last born CEOs are destined for the prison cell. Rather, last borns simply have a tendency to defy authority. Because they tend to resist being pushed around, they'll likely serve as a "human shield" and go to bat for you as an employee.

Only Children

Only children have never needed to compete with siblings for attention. This undivided attention instills in them a strong sense of entitlement. Not surprisingly, only child CEOs tend to be highly demanding and exert supremacy.

You'll find these traits engrained in only child Jack Welch. His prescription for success? To wield supremacy. "As you lead a group of people, you have an obligation to let them know where they stand."

Another classic only child, Carl Icahn is known as a "corporate raider." He has an ironclad reputation for leading hostile takeovers involving the likes of TWA, Nabisco, Time Warner, and Yahoo. He's made it a practice to acquire large stakes in corporate giants and overthrow management. In a fittingly self-confident manner, he's stated, "I think in the takeover business I would say I'm as good as anybody in this area."

CEOs come in all shapes and sizes. Discerning your CEO's birth order can help you understand his/her persona, what you can expect from your interactions with him/her, and the likely trajectory of your company while he/she is in the driving seat.