The phrase birth order refers to the order of birth. Children with siblings are "firstborn" or "laterborns". Alfred Adler noted how later borns vary depending on family size. Children with no siblings are "only children".
The influence of birth order is still an open issue, but some clear patterns have been established.re good
Personality is clearly and strongly influenced by birth order. Personality psychologists largely (though by no means without debate) agree that the Big five personality traits (also known as Five Factor) represent something like a natural taxonomy of human personality variables. Cross-linguistically the vast majority of adjectives used to describe human personality fit into one of the following five areas, easily remembered by the acronym OCEAN: Openness, Conscientiousness, Extraversion, Agreeableness, and Neuroticism.
In his book "Born to rebel", and in ongoing research papers, Frank J. Sulloway has mounted evidence that hi order effects on the Big Five are strong and very consistent. Using a scale between bipolar adjective pairs (ex.: hard-working . . . . . . . lazy) and intrafamily ratings with tens of thousands of respondents Sulloway has shown firstborns to be more conscientious, more socially dominant, less agreeable, and less open to new ideas compared to later borns. In a cross-cultural replication of Sulloway's work anthropologist Paul Roach collected several hundred within-family ratings among horticulturalist Shuar Indians in Ecuadorian Amazonia and found nearly identical correlations between the Big Five and birth order among these nonwesternized people (conference presentation: HBES, 2002, Rutgers University).
Summary of the findings of Belmont and Marolla. Scores on Raven's Progressive Matrices relate to birth order and family size.
hi people Birth Order and Intelligence: A Classic Study
In 1973, Lillian Belmont and Francis Marolla published family size, birth order and intelligence test (Dutch version of the Raven Progressive Matrices) data from nearly the entire population of 19-year-old Dutch men (386, 114 subjects). Their study design was complex, so interested readers should consult the primary source. However, a general overview of the results will be presented here. Belmont and Marolla found that:
"Children from large families tend to make poorer showings on intelligence tests and on educational measures, even when social class is controlled."
"Within each family size (i) firstborns always scored better on the Raven than did later borns; and (ii) with few inconsistencies, there was a gradient of declining scores with rising birth order, so that firstborns scored better than secondborns, who in turn scored better than thirdborns, and so forth."
"In general, as family size increased, there was a decrease in Raven performance within any particular birth order position." For example, a thirdborn born child from a 3-child family would be expected to score higher than a thirdborn child from a 4-child family. A thirdborn child from a 5-child family would be expected to score even lower, and so on.
In 1874 Francis Galton offered several reasons why birth order might affect eminence. Among them, he listed:
Primogeniture laws. First born sons would be more likely have the financial resources to continue their education.
Firstborns had the advantage of being "treated more as companions by parents." This means that they also undertake more responsibility than their younger siblings.
Firstborn children would get more attention and better nourishment in families with limited financial resources
Since 1970, probably the most celebrated theory to explain why firstborns may be more intelligent than laterborns is the confluence model of Robert Zajonc. This states that because firstborns only have adult company about them in their early years, they will spend the initial years of their life interacting on a high intellectual plane. Note well that this will also go for siblings who, although objectively, later born, have a sibling at least five years senior with no siblings in between (technically, these children are considered to be "functional firstborns"). The theory states that firstborns will be more intelligent on the whole than only children, because the latter will not benefit from the "tutor effect" (i.e. teaching younger siblings). Zajonc's theory has been much criticised, especially confounding birth order with both age and family size, and alternative theories (such as Resource Depletion Theory) have been offered to explain the Belmont and Marolla findings.
Birth order and personality
Many claim that birth order influences personality. The realm of pop psychology often attributes the following traits to each order:
Firstborn
The first born child will receive the expectations of his or her parents. Because of this, many firstborns are in danger of acquiring perfectionistic or people-pleasing behaviors. On a more optimistic note, proponents of birth-order theory state that firstborns tend to be quite confident, diligent and mature. Not all firstborns are over-achievers, but even the most laid-back firstborn is clearly guided by a need to do the right thing and strives to make a difference in society. Firstborns can also become uncalm in hectic situations, and tend to "freak out" very easily.
Middleborn
Middleborn children have a diverse range of personalities. The habits of many middleborns are motivated by the fact that they have never been truly in the spotlight. The first-born always seems to be achieving and pioneering ahead, while the younger sibling is secure in his or her niche as the entertainer of the family. The middle born child may develop great social skills and have an easier time growing up with an other-centered point of view. The middle child knows what he or she is doing and tends to become very intelligent, in their strive to gain attention from siblings. Middle born children are usually quite talented, their strive for perfection against their siblings gains access to discover new and unlooked for qualities, musically, academically, and theoretically.
The Youngest
The name given to the youngest child is revealing: the youngest child of the family is viewed as the party animal, the entertainer who is unafraid to test his or her luck. While this is certainly not true of all youngest siblings, proponents of this theory state that the baby of the family is an endearing, delightful friend if not too self-centered.
Alfred Adler's Contribution
Alfred Adler (1870-1937), an Austrian psychiatrist, and a contemporary of Sigmund Freud and Gustav Jung, included birth order dynamics in his theory of personality formation. Also referred to as family constellation, one's birth order position often (but not always) can leave an indelible impression on the individual's style of life (habitial way of dealing with the tasks of friendship, love, and work). Other factors that may be equally influential are: parental attitudes; organ inferiority, illness, and disabilty; gender roles; or social, economic and religious circumstances. Any overburdening factor may intensify normal inferiority feelings and lead to unconscious compensations or over-compensations (i.e, an extremely talented older or younger sibling). Other birth order factors that should be considered are: the spacing in years between siblings; the total number of children; and the changing circumstances of the parents over time. Adler wisely suggested that birth order does not cause any direction of personality development, but it may be used by the individual as a building brick for his/her freely chosen style of life and fictional final goal. Many researchers, in attempting to prove or disprove the sole effects of birth order, neglect the complexity of other influences. dick dick dick dic k dick balz
Belmont, M., & Marolla, F.A. (1973). Birth order, family size, and intelligence. Science182: 1096–1101.
Zajonc, R. B., & Mullally, P. R. (1997). Birth order: Reconciling conflicting effects. American Psychologist, 52(7), 685-699.
Zajonc, R. B. (2001). Birth order debate resolved? American Psychologist, 56(6-7), 522-523.
Herrera, N. C, Zajonc, R. B., Wieczorkowska, G., & Cichomski, B. (2003). Beliefs about birth rank and their reflection in reality. Journal of Personality & Social Psychology, 85(1), 142-150.
Additional material
Books
Papers
Draper, P. & Hames, R. (2000). Birth Order, Sibling Investment, and Fertility among the Ju/'hoansi (!Kung). Human Nature 11, 2, 117-156 Full text
