History

So who started all of this? Where did it come from? Why does this myth even exist??

One of the first theorists to suggest that birth order influences personality was Alfred Adler. His argument was that birth order can leave an impression on one’s style of life, including the way they handle situations such as friendship, work, and love. He claimed that when a second child comes into the picture, the first born are “dethroned” and that may influence them forever. According to Adler, the younger children and only children are spoiled and pampered, which can affect their personalities. Additional birth order factors that he considered are the spacing in years between siblings, the total number of children in the family, and the changing circumstances of the parents over time.

Since Adler's time, the influence of birth order on the development of personality has become a controversial issue in psychology. One of the more modern theories on personality states is the big five. The big five traits are openness, conscientiousness, extraversion, agreeableness, and neuroticism. These traits are most commonly used in more recent approaches and are often used as a measure when performing studies.