Self-Fulfilling Prophecy
For example, a mother may reason, "Oh, Twin A was born first. She is always first to do everything. She was the first to crawl, and she'll be the first to walk also!" She expects her firstborn twin daughter to walk before her sister, and spends more time coaching and encouraging this daughter in this skill. In reaction to her self-fulfilling prophecy, Twin A naturally walks first. As the twins grow up, their parents expect their "firstborn" to look out for her "younger" sister, establishing Twin A in the dominant role in the relationship, and galvanizing her personality traits in the mold of an elder child.
Remember the Biblical story of Jacob and Esau? In chapter 25 of Genesis, it clearly states that their father, Isaac, preferred the firstborn Esau, while the mother, Rebekah, loved only Jacob. This created jealousy between the twins, and ultimately Jacob tricked his brother out of his birthright.
Advice for Parents of Multiples
I believe that parents of multiples have a vital responsibility to foster their childrens' individual personalities outside of the realm of birth order. To accomplish this, they can:
- Adopt a consistent, neutral set of expectations that will allow each child to fulfill their inherent personality destiny
- Avoid birth order stereotypes that are meaningless for twins
- Downplay the signifcance of birth order; if necessary, choose not to identify the multiples' birth order
- Discourage others, including extended family, teachers and curious strangers, from overemphasizing birth order importance

