Birth Order and Twins

What is birth order?

One of the first questions that people often ask my twins is, "Who was born first?" This inquiry always annoys me, and it frustrates my daughters, as well. For one thing, they don't know which of them was born first! My husband and I haven't divulged that information because we didn't want it to become a point of contention in their relationship. We've always joked that we'd have an elaborate unveiling party and tell them on their twenty-first birthday.

But as they grow up together, I don't think that they really care. So why does the world seem to care so much? Does birth order really have any relevance to twins?

What is birth order?

There has always been a lot of interest in the study of birth order and its impact on society. Certainly, throughout history, there have been occasions when determining a child's placement in the family was of utmost importance. The birthright of firstborns meant an opportunity to inherit family fortunes, even entire kingdoms, along with the burden of responsibility for the remaining family members.

Scientists have done some interesting studies to evaluate the role of birth order in the development of personality. Many agree with a 1998 study that said, "Children's perception of their place in the family constellation influences how they feel about themselves, and how they interact with others." (Kottman & Johnson, 1993 in Nims, 1998) Some studies have theorized that first born children have more self-esteem and higher IQ's while lastborns tend to be more relaxed and irresponsible.

Adlerian Birth Order Characteristics

Psychologist Alfred Adler, a contemporary of Sigmund Freud, defined a set of characteristics to describe how a child's position within the family would actualize in his or her personality. The table below presents a simplified version of his theories adapted from the Adler Institute website.

PositionFamily SituationCharacteristics
OldestDethroned by next child. Has to learn to share. Parent expectations are usually very high. Often given responsibility and expected to set an example.May become authoritarian or strict. Feels power is his right. Can become helpful if encouraged.
SecondHas a pacemaker, always someone ahead.Is more competitive, wants to overtake older child. May become a rebel or try to outdo everyone. Competition can deteriorate into a rivalry.
MiddleIs "sandwiched" in. May feel squeezed out of a position of privilege and significance.Even-tempered, "take it or leave it" attitude. May have trouble finding a place or become a fighter of injustice.
YoungestHas many mothers and fathers in older children. Never dethroned.Wants to be bigger than the others. Can stay the "baby." Frequently spoiled.

Where do twins fit into the birth order equation? Psychologists agree that birth order characteristics are most often imprinted within the first few years of life. However, with twins, there is usually only a matter of minutes between births, not years. Does any significant event happen in those few minutes that would influence the individual child's perception of his or her position within the family?

Not usually.

Who's "on" first?

Birth order for twins isn't necessarily preordained, either. The babies' order of birth is determined by their position in the womb, which can change throughout pregnancy. In some cases, which baby is born first depends on how the mother delivers; the order might be switched if the mother had a Cesarean section rather than vaginal delivery.

So how do you explain the manifestation of birth order characteristics in the personalities of individual multiples? Certainly, there are many examples of twin sets where the first born twin is a dominant leader and the second born is a subdued follower. Is that because of their birth order or is some other factor at work?

What the Experts Say

​Unfortunately, there isn't a lot of specific research available on this subject. However, many birth order experts agree that twins tend to organize themselves according to their overall place within the family.

For example, if they have one older sibling, they will both exhibit characteristics of a second born. If they are the oldest, they will adopt some traits of first firstborns.

However, Cliff Isaacson, author of The Birth Order Effect as well as the website Birth Order Plus, further believes that birth order traits in twins are also impacted by their status as twins.

He explains, "The organization seems to result from one of the twins being dominant, resulting in that one having the older Birth Order. It does not seem to have much relevance to the order in which they were actually born. The Birth Order personalities of twins are often more intense than in normal Birth Order. Because they are the same age and capability, the dominant one has to work harder at being dominant thus reinforcing the Birth Order personalities of both."

When strangers realize that my twins truly don't know who was born first, they often try to guess based on their perceptions. "You must be born first, you are -- fill in the blank here -- taller/have longer hair/are more outgoing than your sister," they say, trying to pinpoint a dominant characteristic. What they don't realize is that by tomorrow, the sisters may have switched these traits! Psychologists agree that twins often exchange dominance throughout their lives, and in that sense may alternate between birth order categories.

Aside from inherent personality traits, I believe the impact of birth order in multiples is more often one of perception rather than reality. Parents of multiples, as well as society, apply behavioral expectations based on traditional birth order characteristics; in reaction, the individual children behave in fulfillment of those expectations.

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 children's' 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

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