image: source

The family album of a large brood will sport countless proud photos of baby number one.  Baby two will have significantly less and so on down the line until number six will be lucky to get a name never mind a photo.  It is this unfair, but pretty unavoidable division of parental attention that researchers say can cause personality differences among siblings.

If popular theory holds true then first borns should be superior, controlling, yet carry the weight of the world on their shoulders.  The second born will be competitive, and the last born manipulative and rebellious.  The only child will of course be self-centered.

Alfred Adler (1870-1937), the Austrian psychologist, first put forward theories about birth order.  The eldest child, overloaded with responsibility and high parental expectations, would be the most likely to become neurotic, depressed or turn to substance abuse possibly ending up in jail or a mental asylum!   He would sustain feelings of ‘dethronment’ when the second child arrived.  The youngest child would be spoiled and may try to be ‘bigger’ than the others, having grand plans which never amount to anything.  An only child would become a rival of one parent.  Interestingly, Adler predicted the middle-born (commonly thought of as ‘the problem child’) to be the one most likely to develop into a successful individual, having been neither ‘dethroned’ nor pampered.

Adler’s theories influenced popular beliefs about birth order.  But research has shown that, rather like astrological star-signs, people tend to perceive birth order characteristics once they know an individual’s birth rank.  Not all psychologists agree upon how much birth order affects character development.

Judith Rich Harris (psychologist) says there is evidence that peer group has more influence than birth order and a child will learn to behave differently outside the family home.  For example, an eldest child, used to being ‘top dog’ at home, may find himself the ’shrimp’ in the playground and this will affect his behaviour.  Harris concedes that “birth order effects do exist within the context of the family.  When they are with their parents and siblings, first-borns behave differently from later-borns – even in adulthood”.  This could be why family reunions are so often fraught with emotion.  We are reverting to childhood patterns almost against our will.

Detractors of birth order theory say that because personality is affected by so many variables it is impossible to conduct studies on an level playing field.  Parental attitudes, socio-economic status, religion and culture all create such a unique set of circumstances that it is irrelevant to compare one family with another.  But within each family, rank matters.

In 2007 a Norwegian study found first-borns to have a slightly higher IQ than subsequent siblings.  But the results also showed that second-borns with an elder sibling who died in infancy had IQs on a par with first-borns.  This suggested that social rank in the family was more significant than birth rank.  Other studies have shown that if there is a five year or more difference between siblings a ’sub-group’ may form, with the eldest in the sub-group displaying similar characteristics to a first-born.

Frank Sulloway (Universtiy of California) says personalities of siblings vary because they adopt different strategies to gain parental favour.  Elder children strive to keep their parents attention through conformity whereas last-borns, feeling the ‘weakest’, use ‘low-power’ strategies like making people laugh.  Sulloway’s research on political activism found that later-born political activists are more radical than first-borns, who tend to identify with authority.  Richard Zweigenhaft (psychology professor) conducted a study of protesters at a labour demonstration and found the majority of people arrested were last or later-borns.

In a study of the effects of birth order in the workplace, Ben Dattner (New York psychologist) found that first-borns were more ambitious and disciplined, but also more fearful of losing rank and defensive about mistakes.  Second-borns were more open to new experiences.  He found they were more relationship focused and concerned with justice, less academic but better at using social intelligence and humour.  Middle borns were good at negotiating and peacemaking and were more easy going, usually closer to friends than family.  Only children were achievement oriented but were inclined to do work themselves rather than delegate.

Other surveys have shown that firstborns are more likely to pursue ‘intellectual’ careers and are in higher paid professions, whereas lastborns earn the least and are more likely to be in creative occupations or jobs involving some physical risk.  Middles seem to be highly represented in ‘people’ jobs such as nursing or law enforcement.  A survey of company CEO’s found that 43% were first born, 33% middle born and 23% last born.  More than half of all US presidents have been first borns.

So, do these famous names fit the theories?

First born -  Brad Pitt, Oprah Winfrey, Bill Clinton, Hilary Clinton, Winston Churchill
Middle – Britney Spears, Madonna, David Letterman, Richard Nixon, Princess Diana
Last born – Janet Jackson, Cameron Diaz, Jim Carey, Billy Crystal, Steve Martin
Only child – Pamela Anderson, Tiger Woods