Kiernan. Pathway to Adulthood and Marriage: Teenagers’ Attitudes, Expectations, and Relationship Patterns. http://aspe.hhs.gov/hsp/08/pathways2adulthood/ch1.shtml. 25 March. 2014.
In an article she wrote about birth order and personality, she claimed, the reason all your siblings are so different is not because they came out of their mother's womb at different time, but it is the fact that his/her parents treated him/her a certain way. If you are first born, naturally, you get all the attention and are like an experiment for the new parents, and this is what shapes his/her attitude or behavior. The fact that middle born children are born into a family with already another child, immediately changes how their parents treat them from the first born. They never will know what it is like to have complete attention all the time from both their parents. This teaches middle children to share and be independent starting from birth.
Web. 26 Feb. 2014
"Family Formation and Raising Children Among Same-sex Couples." http://williamsinstitute.law.ucla.edu/research/census-lgbt-demographics-studies/family-formation-and-raising-children-among-same-sex-couples/. The Williams Institute, Jan. 2012. Web. 18 May 2014. http://www.christianalliancefororphans.org/resources/orphan-facts/orphan-facts-global-orphan-care/.