The study of birth order, it’s
effect on who we are, and effects on later life, can be traced back into the
very roots of history itself, with greats such a Darwin being affected by the
role of birth order plays in who we become.
This essay will argue the main
cause of our behaviour and consequently the kind of person we become, is due to
our birth order. As it causes adaption to strive for parental resources as a
child. Therefore, this competition for resources, creates the foundation for
our behaviour, and consequently the people we become.
One of the most significant areas
of birth order, to effect behaviour, is that of a firstborn’s reaction to the
birth of another child, and consequently the strive to compete for parental
resources that this causes. This is evidenced in the findings of Pollet et al.
(2010, p.744) that state “The overall effect of birth order lost it’
s marginal significance, but the
contrast between firstborns and other birth orders remained significant” It can
be inferred from this evidence, that birth order can be seen to effect
behaviour most, when considering the change from only to first born child.
Furthermore, when a new child is born, it can exacerbate
behavioural changes, as parents have to find a balance between sharing precious
resources amongst children within all stages of birth order. This has been
suggested to have “profound effects on offspring survival” In research carried
out by Hill and Hurtardo (1996 cited Courtiol, Raymond and Faurie (2009, p.1405)
. Therefore, it is unsurprising that the threat of a new child can have effects
on behaviour. Similar was suggested in Courtiol, Raymond and Faurie (2009, p.1406)
as it stated that parents are more likely to invest in the firstborn child. This
is due to firstborns having already survived the most dangerous first years.
Therefore, the benefits of being firstborn in the allocation of parental
resources, are shown to put laterborn siblings at a disadvantage, which will
lead to them having to adapt behaviourally to gain parental resources.
Consequently, creating competition between siblings and affecting behaviour in
ways that impact the type of person we become.
Another way that birth order can
instil behavioural change within children, is through the effect that
competition for parental resources itself has on development. The reaction of
the firstborn to the laterborn children, creates competition which manifested
itself in different ways; It can exhibit itself in un-cooperative behaviour, as
firstborns try to regain Parental resources, by acting in a rebellious
manner. Sulloway (1996) study agrees with
this point as it states that “Firstborns have more reason than laterborns to be
jealous of their siblings. Every firstborn begins life with 100 percent of
parental investment” Sulloway (1996, p.70).
This therefore creates an environment for firstborns to develop poor
behaviour traits, in competition to regain parental resources lost to
laterborns, a particular set of behavioural traits that are said to be
developed are “Anger and Vengefulness” Sulloway (1996, p.70). Therefore, this
would suggest that birth order does have some sort of effect on behaviour,
especially when considering the effect, competition for parental resources has
Alternatively, another effect of competition
created by birth order can have on siblings is demonstrated in Courtiol,
Raymond and Faurie (2009, p.1410). Reasearch states “firstborns tend to favour
cooperation within the family”. This behaviour can manifest itself in the
firstborns eagerness to become a surrogate parent to the laterborn child.
Sulloway (1996, p.21). states that ” Eldest children… are likely to seek
parental favour by acting as surrogate parents.” This behaviour is explained as
the child competing with siblings to regain some parental resources by gaining
parents favour. This would also suggest that competition created as a result of
birth order does have some sort of effect on behaviour. As firstborns are
actively changing their behaviour to fit a new family dynamic.
The way that siblings learn to deal
with the competition created by parental resources, does lead to an effect on
adult behaviour. As evidenced in Courtiol, Raymond and Faurie (2009, p.1409). “siblings
seemed to develop distinct cooperation strategies based on their birth order,
which had long term effects on cooperation between unrelated individuals in
adulthood”. This evidence is significant as it demonstrates that, behavioural
traits not only continue to effect family life into adulthood, they also effect
behaviour when considering unrelated persons.
Lasting effects of birth order are
also demonstrated in the research by Pollet and Nettle (2009 cited Pollet et al (2010, p.744) “Firstborns
could indeed be more dominant than laterborns. Yet in samples of adults this
pattern could be reversed, as there is no pressure for firstborns to behave
dominantly when competition for parental resources ceases to exist”. This
evidence is important as it identifies, when competition for parental resources
isn’t necessary, an adult can revert back to a less dominant behaviour.
Therefore, this proves that an effect is had by Birth order on behaviour as
when the stimulus (Birth Order) is removed an adult is able to revert back to
previous behaviour, this evidence that it was birth order that created this
behavioural change initially.
Overall, when considering, in what
way does birth order affect the kind of person we become. It is evident from
work in studies like Courtiol, Raymond and Faurie (2009.) “siblings seemed to
develop distinct cooperation strategies … which had long term effects on cooperation”
that a child’s adaption to the behaviour of other siblings in competition for parental
resources, does have a lasting effect on our behaviour, and consequently the person
we become. Furthermore, it is argued in this essay that reaction of a firstborn
child to a laterborn is a significant part of birth order and it’s behavioural
effects, this was proven by the effect that the competition created was shown
to have on adults in later life in Courtiol, Raymond and Faurie, where it was
found “siblings seemed to develop distinct cooperation strategies based on
their birth order, which had long term effects on cooperation”. In summary, I
believe that birth order and the effect that it has on the kind of person we
become though competition for parental resources is clear.
However, further work is needed on
birth order, and it’s effects. Especially when considering, the work on the
lasting effects of birth order on siblings and the behavioural characteristics
of adults. Further experimental study, would help to reinforce ideas discussed
in this essay.