Firstborn children have ‘infinitesimally small’ IQ lead over siblings

FIRSTBORNS have consistently different personality traits compared with their younger siblings, a new study finds. And what is more – they generally have higher IQs. But the differences are so minimal, the study authors warn, that they will make no noticeable impact on anyone’s lives.

Some studies have suggested that firstborns show higher levels of intelligence as a result of being afforded more ‘intellectual stimulation’ by the family.

The order in which we and our siblings are born is widely believed to influence the people we become. For instance, there are many bestselling parenting books that claim birth order makes a difference to children’s personality, intelligence, development and future success.

However, scientific evidence to support this claim has been inconclusive and controversial.

The authors of the new study note that “one of the most heated scientific disputes of all time” erupted over a disagreement on the extent to which birth order influences development. Psychoanalysis leaders Sigmund Freud (a firstborn child) and Alfred Adler (a middle child) clashed over the latter’s claim that first- and lastborn children are burdened by neuroses as a result of their struggle for superiority, while middle children are more healthy, easygoing and rebellious.

The schism between the psychoanalysts was so deep that Adler was forced to resign his presidency of the Vienna Psychoanalytic Society, which met Wednesdays in Freud’s apartment.

In modern times, scientists tend to favor evolutionary theory, which partly agrees with Adler’s hypothesis, suggesting that siblings fulfill different niches in an effort to compete for parental attention. In this theory, the firstborn tends to be more responsible and concerned with parent-pleasing, whereas laterborn children are more rebellious and sociable.