I noticed that all of you that have responded so far have multiple siblings. There has been a tremendous amount of research that discusses the traits of individuals and how that is related to the birth order, or standing, they had in their family. For example, some studies have found that oldest children are more responsible, middle children are the "peace makers" while the babies of the family have no sense of responsibility at all.
Look at your own birth order, do you think that has affected who you are today?
While researching birth order, specifically for the middle child of three, I found that I have several traits that are characteristics of the middle child syndrome. These traits are (Dinkmeyer, McKay & Dinkmyer, 1978):
Has neither rights of oldest nor privileges of youngest.
Feels life is unfair.
Feels unloved, left out, "squeezed."
Feels doesn't have place in family.
Becomes discouraged and "problem child" or elevates self by pushing down other siblings.
Research about multiple siblings is presented.