Psychology: Nature vs Nurture debate

essay by cheryl yow



Question:
Mr. P was a bombardier during World War II.
During his ninth mission, his airplane was severely damaged
and started to nose dive. The pilot regained control just
in time to avoid crashing the plane. However, during the
dive, Mr. P was seriously injured. After an interim recovery
period, Mr. P was sent back to duty.


On his two subsequent missions, he fainted. One analysis of
his reactions stated that his fainting was connected to deep
underlying anxieties, and that he was basically an immature
person with long standing insecurities. The near-fatal
accident was trivial.


A second analysis of Mr. P’s reactions suggests that the
fainting was a direct result of being in a situation
similar to the traumatic one previously faced.
Can both analyses be correct? Discuss.






Psychological personality theorists are increasingly
appreciating the nature and nurture debate. Is
personality determined by our genes or is it shaped
through our interaction in social contexts influenced
by the environment? Eysenck (1967) claimed that specific
part of our brain dictates our behaviours and thus our
personality is rooted in biology. In contrast to Eysenck’s
theory, Zuckermann (1995) suggests a new direction: it is
neurochemistry and associated physiology that connects
personality rather than brain anatomy. These suggest
biology shapes our personality:openness,
conscientiousness, extraversion, agreeableness and
neuroticism (the five factors of Costa and McCrae’s
theory of personality).



The fact that Mr P was a bombardier before his accident, he
must have been through a challenging, grueling training
and had emerged as a calm and confident aviator. If we
attribute these qualities to genes than it may be
suggestive that he has ‘confident’ genes. However, his
fainting happened only after the ‘nose dive’ accident and
not before that, it is quite rational to conclude that his
fainting is due to his reaction to his past horrifying
‘nose dive’ experience of the plane. In other words, his
fainting was influenced by the environment rather than his
genes. We will look at some interesting views on the
nature versus nature debates followed by the
inadequacy of the twins’ studies of heritability;
and the famous ‘mock prison’ psychological study
that reveals the potency of the environment on human
behaviours and lastly a glimpse of the neglected idea
of ‘free will’ in the midst of nature versus
nurture debate.


Can our behaviours be due to uncontrollable genetic
impulses? Caught shooting, blame it on your genes, you might
argue ‘it runs in the family’ or argue for temporary insanity.
If drugs like Prozac, an antidepressant work by modifying the
activity of neurotransmitters, it seems realistic to believe
that inherited genes can produce chemicals and impact an
individual’s behaviour dramatically. And interestingly, in
debates surrounding cloning, there is a far-fetched
idea that a Mozart or Hilter could be re-created
through genetic cloning. Could cloning make
someone entirely identical? And if genes do
contribute to genius than how come we never heard
of the siblings of Darwin, Bach or Gandhi? On the
other hand, some deterministic models of human
behaviour try to define the role of the natural environment
 – for instance some psychological biometeorologists have
found that rising summer heat lead to mounting levels of
rapes and assaults. It is also found that people most likely
make their wills in Spring, homicide rates are greatest in
the South and accidental death rates are the highest in the
Southwest. What determined our destiny? Was Mr P
not destined to die on that dreadful trip? If anything
happens, do we believe that our destinies are
predetermined, whether by genes, our environments,
or by God? And since we cannot prove the existence
of God, we are left with either – genes or the
environment.


In order to assess the impact of genetics and environment
contribution to personality, behaviour genetics used the
study of heritability. The studies of twins are prominent
in heritability. Studies on twins is based on ‘equal
environment assumption . Those rear together in the same
environment/family was assumed to be similar while those
rear apart in different environment/families was expected
to be different.In 1992 Loehlin re-analysed all the twins
findings from around the world and his findings confirmed
the estimate of neuroticism to be 0.31. Although biological
components of temperament and personality are innate to
quite a considerable degree it still account to less than 50
percent. Additionally, It is a mistaken view to assume that
children growing up in the same environment will have the
same experiences. Even within the same family each
child will react and adapt according to the influences of
the environment and these generate differences in their
behaviours resulting in their individual distinct
personalities. Children may also unwittingly assumed the
personality of their caregiver (nanny/maid) who are not the
immediate family members. Besides, parents may also try to
adjust either by matching or unmatching their children’s
behaviour in order to construct their personality. Thus
the assumptions that the environments are ‘being equal’
is questionable.



Furthermore, genes studies have provided nothing more
than tantalizing clues to discovery of genes controlling
addiction, thrill-seeking and even sexual orientation. No
one has identified a "gay gene". In Britain, King &
McDonald, working from an AIDS clinic, found 45 homosexuals
who had twins and that 25% of identical twins shared their
co-twin's homosexuality, compared with only 14% of fraternal
ones. The percentage here is low. Whereas in Scandinavia,
researchers’ study of 45,000 pairs of twins has shown that
cancer is chiefly triggered by the environment rather than
inherited genes. Colon cancer is usually link with a
faulty ‘colon cancer’ gene. This mutated gene exist
in every cell although cancer only appears in the
colon triggered by toxins produced by bacteria,
so cancer is in fact an environmental disease.



Thus, genetics cannot entirely justify the biological
differences in our behaviour. The genotype needs an
environment to interact in order to produce the phenotype.
The famous psychological study of Zimbardo (1975)
proved the powerful influence of the environment on
human behaviours. In this study, college students playing
the roles of prisoner or guard in a mock prison resulted
in a shocking revelation:
‘Less than 36 hours into the experiment prisoner
#8612 began suffering from acute emotional
disturbance, disorganized thinking, uncontrollable
crying and rage.’
( MP1, p 331)



Another prisoner of many years played the role of a
‘prison consultant’ has become the most despicable
authoritarian official. When the study ended he could not
believe it and felt sick at what he had become. Video tapes
also revealed ‘Prison guards’ ill-treating the‘prisoners’
when they believed that the experiment was off and that
researcher were no longer watching them. The role-plays were
so potent that ‘prisoners’ soon become demoralized, out of
touch with reality and began to show sign of severe stress
that the study was stopped immediately after 6 days
although planned for 2 weeks. It is disturbing to know that
ordinary, intelligent, mentally sound college students
could so easily become perpetrators of malevolence due to
the potency of environmental influences.


Though the environment remains a compelling determinant of
behaviour, the principle of the ‘nature versus nurture’
debate seems to deny the importance of ‘free will’. Human
behaviours are different from animals. Animal behaviours are
instinctive whereas humans are aware of their actions and
those of others. Instincts make behaviours the ‘puppets’ of
the environment. The rooster crows at dawn and frogs croaks
with the stimulus of rain, their behaviours were dictated by
the environment.



Humans have the fewest instincts among mammals thus we do
have behaviourial flexibility and environmental adaptability.
However culture learning ensures that behavior is similar
for members belonging to the same community. Presently,
heritability twins’ studies account to only 30%, this
evidence is not convincing whereas we have seen how potent
the ‘mock prison’ study (environment) is in the total
transformation of personality. The existence of gene does
not by itself warrant that a particular trait will be
manifested. Without the specific environments the innate
propensities cannot be fully expressed. Although it seems
more compelling to believe that the environment rather
then genes contribute more to our behaviour/personality,
the most significance thing is we are endowed with ‘free
will’. Therefore, biology may prescribe our abilities,
and the environment its manifestations but free
will still dictates what we do with these abilities.
Mr P in this case is influenced by the environment,
however, he could choose ‘free will’ to overcome his
fear. ‘Life is like a game of cards. The hand that is
dealt you represents determinism; the way you play
it is free will’. (Jawaharlal Nehru).


(1273 words)




Bibliography
Meill, D. et al, (2002). Mapping psychology 1, United
Kingdom:The open university.

Dr Kelvin Davies. ‘Nature vs Nurture revisited’.
Retrieved 6 September 2007
http://www.pbs.org/wgbh/nova/genome/debate.html

‘Nature versus Nurture’ . Retrieved 10 September 2007
http://en.wikipedia.org/wiki/Nature_versus_nurture

Nature VS Nurture: How much free will do we have?
Retrieved 10 September 2007. http://www.trinity.edu/mkearl
/socpsy-2.html




Tutor Comment:
You’re one of the few who chose to respond to this question.
You did a good comparison of the nature and nurture
positions in psychology. You promoted the notion of free-will,
although strictly speaking you didn’t provide empirical
evidence to support it – as a person, you believe in the
essence and inviolability of free-will, and this carries over
to your essay. The other position you could have elaborated on
is interactionism – behavior is a result of the interaction
between genes and environment, and this can account for P’s
behavior.

Overall, a good essay!

Grade: 52/60