It's long been speculated that birth order has an effect on personality. Specifically, that first born children are driven, middle children are wild "black sheeps" and the babies of the families are spoiled and lack focus. It is now thought that the effect of birth order on personality is much more diverse and complex. Of course birth order affects those born into a family or two, four, five, etc, but those are most likely derivations of the three primary. So, in the interest of simplicity, let's focus on the latter—first, second and last born children.
First born children are welcomed into a tightly primped environment riddled with elevated standards and high expectations. New parents are attentive, proud and well-read. They take a roll of pictures a day, buy only the finest diapers and don't let a single achievement go unnoticed. All of this can have a very positive effect on a first born child. These children often develop a diverse vocabulary at an early age, are independent, strong-willed and able to adapt easily to many situations. First born children are known to be highly organized and eager to please (probably a result of the constant attention they received as youngsters). They are often excellent leaders, as well, pursuing careers in education, entertainment, politics and entrepreneurship.
Children can also be negatively affected by being first born. Amateur parents' inevitable anxiety can often seep into a first born, resulting in a lifetime of worry and self-consciousness. Secondly, first born children often take on the role of "Peace Maker"—attempting to resolve familial problems. They mediate and abstain from initiating more conflict as to avoid disappointing their parents. This can lead to perpetual passive-aggressiveness. First born children also tend to be over-achievers and can be greatly discouraged by perceived failures relating to school, career or personal relationships. On a similar note, children born first are showered with attention, leaving them with a sense of inferiority and resentment when the second child arrives.
Second born children are competitors. They may feel inadequate in comparison to the older sibling, regardless of whether this feeling is perpetuated by the parents. Phrases like "why can’t you be more like your brother" or "your sister wouldn't do that" are often associated with the fate of the middle child. Adding fuel to the fire, the older child is perceived as doted upon and privileged. These circumstances can cause the middle child to harbor intense resentment for the first born child. This, combined with the need to compete may lead to rebellion and isolation. That being said, second born children are often the most troublesome of the three. They exhibit this behavior in an attempt to receive the attention that is constantly given to the older child. They also tend to act out when a third child is born because they feel even further neglected. The parents are juggling a newborn, to whom they must constantly attend, and an older child who needs endless encouragement because they are trying things for the first time. This can lead to a flexible and carefree or stubborn, "fight or flight" attitude on the part of the middle child.
On a more positive note, middle children are often artistic, witty and incredibly self-sufficient. They are afforded the luxury of being able to depose the oldest, at the same time taking control of the youngest; this can help boost an otherwise deflated self-esteem. The inherent flexibility associated with their place in the birth order may help middle children easily conquer a variety of social situations and stressors. They also tend to develop many loyal, long-lasting relationships outside the family, perhaps as an effort to feel included. Parents should keep in mind that these relationships can turn sour. Sometimes a middle child will seek rebellious social groups as a means to stand out and be noticed—an attempt to compensate for the lack of parental attention.
Last born children are the offspring of increasingly mellow parents. Consequently, the lack of parental anxiety is replaced by constant adoration and affection. These children have their parents sitting prettily in the palms of their hands. They are not, however, readily welcomed by children preceding them. The baby of the family is often revered as the one who stole the spotlight. They are showered with attention and are rarely held accountable for blunders. Children born last also cannot be dethroned—their place in the family will never be compromised. That being said, babies of the family are often less competitive than are their older siblings. However, they do lean toward rebellion (e.g. dangerous sports) in an attempt to counteract being bossed around. Their parents' lax approach to child rearing often rubs off on the last born, resulting in a very happy-go-lucky personality. Last born children are often even-tempered, creative, charming and affectionate.
On the contrary, there are pitfalls associated with being born last. Parents have a tendency to over indulge the last born child, which can lead to a lack of self-control (e.g. alcoholism, gambling addiction). Last born children can also be manipulative in adult relationships because they are accustomed to being spoiled. On that note, parents often experience a certain degree of sadness when raising their last child; sort of an empty nest-type feeling. This can lead to a tendency to be over-protective and codependent. In this case, a last born child may become needy and lack the desire to become independent.
Some famous first born children: Bill Cosby, Hillary Rodham Clinton, Oprah Winfrey, Winston Churchill, Rush Limbaugh and presidents Bush (George W.), Johnson, Carter and Truman
Middle children: George Washington, Cindy Crawford, Richard Nixon and John F. Kennedy
"Babies:" Margaret Thatcher, Jay Leno, George Michael, Sir Laurence Olivier and Jim Carrey