While it is generally accepted that many other factors play a large role in a child's development, and many play a larger role than birth order, it is hard to deny that for most people, their birth order does influence a few standard personality traits.
First born children are known for being strong problem solvers and learners, active goal setters, ambitious and energetic, schedulers, good in teams, and great leaders. On the flip side, they can often be overbearing, too critical, convinced that they are right in all situations, prone to spend time overanalyzing a situation, and run the risk of failing to see the big picture.
Middle children are known for being very realistic, trend setters, diplomats, extremely trustworthy, and the least spoiled of the birth positions. On the flip side, they can often be overly rebellious, cynical and suspicious, stubborn, and have such a great fear of embarrassment and confrontation that they fail to let others know when they need help or have problems with another person or situation.
Last born children are known for being tenacious, relaxed, very funny and entertaining, extremely people-oriented, and always nice to be around. On the flip side, they can often be manipulative, a bit absent-minded, self-centered, and a little bit flaky.
Only children often join aspects of first and last born children. They tend to be very driven and focused. They may have added feelings of incompetence — as their only comparison through childhood is with adults, but may also be more socially and intellectually mature at an early age as a result of more focused stimulation from adults.
The study of birth order is far from a science, and it is important to keep in mind that while some of these traits may manifest in a child, many may not. A number of social theorists have proposed that with lowering birth rates in the first world, we are becoming a nation of more focused individuals, as a result of the increased prevalence of only-child homes.
Also of interest is the growing phenomenon of children who occupy more than one position in birth order — or have that position changed immediately. This occurs when a family unit breaks up, and then the parents remarry, perhaps to others who already have children. So it may be that an only child remains an only child when staying with her father, but has three half-siblings while staying with her mother.
