Birth order has been noted to be important in family relationships since Biblical times.  (Remember the stories of the sibling rivalry of Cain and Able as well as the tension between Jacob and Esau as they fought for their father’s blessing.)  Francis Galton in 1874 was the youngest of nine siblings, and he analyzed a group of English scientists, finding that firstborns were overrepresented.  After studies in the 1900s seemed to discount the theory that birth order contributed to an individuals’ intelligence or personality, the topic was shelved. However, it resurfaced in the 1960s when psychologists noted that 21 of the first 23 astronauts were firstborn.

Although controversy still surrounds this topic, birth order can give us clues to a child’s development of intelligence and personality traits and help us parent appropriately.

When looking at family dynamics through the birth order ‘lens’, there are three main birth order positions – the first born (including ‘only’ children),  middle born children (including second born), and the last born (the baby of the family).  There are variables that might impact the influence of birth order and need to be taken into consideration. 

1. The sex of the children.  If the first born is a female and the second born is a male, the second child may have some traits of a first born because he is a different sex than the firstborn.
2. The age difference between children.  If there is a difference of five or more years, it is as if a ‘second family’ has been created, so the younger child may take on some characteristics of a firstborn.
3. Different physical characteristics or abilities.  If a younger child is taller or more athletically inclined than the older child, for instance, there may be a ‘role reversal’ in the family.
4. Parental birth order is an important consideration.
5. Twins or other multiple births occupy a unique position in the family and usually impose a great amount of pressure on younger children.  Family dynamics may be greatly altered when twins enter a family and birth order concepts are disrupted.
6. Blended families will see children adjusting to new relationships as their birth orders often change.

Many other forces can contribute to family dynamics and personality development, so the guidelines and generalizations above and listed below are just that – guidelines.  Each individual and each family is unique!

• The first born child
• Second born & middle children
• The lastborn child -- the "baby"
• The "only" child

Although there are many generalizations in this series, we recognize each child and each family are different. However, by understanding the impact of birth order on our children, we can adjust our parenting to help ameliorate some of the negative outcomes that may be related to birth order.

For much more information, see The Birth Order Book by Dr. Kevin Leman. His website, www.birthorderguy.com, also has excellent pod casts on numerous parenting questions.