30-Second Psychology: The 50 Most Thought-provoking Psychology Theories, Each Explained in Half a Minute - Christian Jarrett 2011
Growth & Change
The idea that birth order can have a lasting influence on personality and behaviour was first suggested by the influential psychologist Alfred Adler in the 1930s. Adler argued that the eldest child is socially dominant and intellectual, but tends to seek approval from others because he is no longer the centre of attention following the birth of a sibling; that the middle child, being sandwiched between older and younger siblings, is competitive and diplomatic; and that the youngest child tends to be selfish and demanding, since he is used to being provided for. Adler also stated, however, that although birth order is a contributory factor, it is environmental conditions, such as socioeconomic circumstances, that ultimately shape personality. There is no doubt that parents treat their first and second siblings differently — they can devote more time, attention and resources to, and tend to be more protective of, their first child. With the birth of a sibling, the firstborn loses his status as the only child, and the parents divide their time between the two. This differential treatment could plausibly affect the children’s personalities, but it is impossible to establish exactly how, because its effects cannot be isolated from those of other factors such as sex, the age gap between siblings and socioeconomic status.
A person’s rank by age among their siblings affects their psychological development and personality.
Although the idea that birth order affects personality is very popular, it has proved to be highly controversial, because there is very little scientific evidence to support it. Many of the studies investigating birth order effects do not take the confounding variables into account. Recent research lends some credence to the idea, however, with one 2009 study showing that lower birth rank has a negative, albeit small, effect on IQ.
KOHLBERG’S MORAL STAGES
If you’re the first born, you get your parents’ undivided attention — but remember, they’ve never done this before!