Nature
Nurture
Both
Schacter and Singer
Sperry
Baron-Cohen
Dement and Kleitman
Raine
Tajfel
Deregowski
Bandura
Hodges and Tizard
Loftus and Palmer
Rosenhan
Hraba and Grant
Gould
Gardner and Gardner
Piliavin
Zimbardo
Thigpen and Cleckley
Milgram
Freud
Samuel and Bryant
Problems researchers have
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Many behaviours are both.
Not possible to isolate one factor to study.
Research might have to be unethical
Research might be low in ecological validity
Environment can affect biology.
Relationships between data are difficult to interpret. E.g. intelligent parents
have intelligent kids.
Much of the research is case study or small samples – difficult to generalise
Ethical implications – e.g. intelligence is genetic – Eugenics
Core Studies 2 revision
The nature/nurture debate
Section B
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a)
Bandura, Ross and Ross (aggression)
Deregowski (perception)
Gould (IQ testing)
Gardner and Gardner (Washoe)
Describe what each study tells us about how behaviour is inherited or
learned. (12 marks)
Is behaviour inherited or learned? The answer to that question is that it depends
on the behaviour. The study by Bandura, Ross and Ross, for example, tells us that
some forms of aggression can be learned, because in this study, the children who
saw it imitated the unusual aggression shown by the models towards Bobo. On
the other hand, some children who were exposed to a non-violent model and to no
model at all also hit Bobo, and this suggests that perhaps some aggression is
inherited rather than learned. Therefore, perhaps aggression is a result of an
interaction between an inherited aggressive instinct and learned acts of aggression.
Deregowski’s study of pictorial perception in different cultures supports the
nurture side of the debate very strongly. In this study, many Kenyan and Bantu
children and adults were unable to see depth in Hudson’s pictures of an antelope,
an elephant and a hunter. This was because they could not perceive the depth cues
of familiar size. Another piece of evidence from the study, which supports the
nurture side, is that the 2D perceivers could draw the impossible trident but the 3D
perceivers could not. This means we learn to read pictures and they are not a
lingua franca.
Gould’s study on IQ testing tells us that such testing is culturally biased, and
although Yerkes claimed he was testing native intellectual ability (your potential
to be intelligent or not), he was actually testing knowledge of American society.
So this study tells us that intelligence, at least as far as how it was measured in this
study, is the result of learning rather than nature. This is shown by the fact that
many of the men who scored low on the test could not read or write, and it was
this that resulted in their low score, not their lack of intelligence.
Gardner and Gardner’s study was about teaching sign language to a chimpanzee
and so favours the nurture side of the debate. They taught Washoe to use signs,
using imitations and rewarding her with tickles when she got the signs right.
After 2 years she could sign 30 signs. This shows that language is learnt.
The example and comment is weak here, but as the rest of the answer is strong,
the candidate still achieves an A grade.
b)
Using examples, give four problems that psychologists face when they
investigate whether behaviour is inherited or learned.
There are a number of different problems that psychologists face when they
investigate the nature/nurture debate. The first is that it is difficult to separate
what is learned during the experiment from what had been previously learned or
inherited. As I have said above, Bandura Ross and Ross’s study tells us that
specific acts of aggression can be learnt through imitation, but the fact that those
children who did not see the aggressive model also behaved aggressively suggests
that their aggression was inherited. Another possibility is that they were simply
showing aggressive behaviour that they had learned before the experiment,
perhaps because they had a Bobo doll at home and had played with it with their
father. This tells us that psychologists find it very difficult to separate learning
from inheritance, and so may never be able to say for sure if behaviour is totally
learnt or totally inherited.
Gould’s Study is related to Bandura, Ross and Ross’ in that both of them find it
difficult to measure if behaviour is inherited or learnt.
The problem with Gould’s Study, however, is that the test use was culturally
biased. If we want to know whether or not intelligence is innate, then we need a
culture free test, because only then can we be sure that we are not testing
knowledge gained from living in a particular culture. Gould’s Study shows just
how difficult this is, because Yerkes believed that he was testing innate
intelligence, but Gould shows us that he was not.
If a behaviour is found in all cultures, then this could be evidence that it is
inherited, since if all humans do it then it is unlikely to have been learned. This
means that psychologists have to do cross-cultural studies like the one done by
Deregowski. His study tells us that depth perception in pictures changes from
culture to culture. The only way that this could have been done was using a crosscultural study. Carrying out cross cultural studies, however, is expensive and time
consuming. Another problem is that psychologists may be culturally biased or
ethnocentric in the way that they interpret the behaviour of the other cultures.
The above paragraph is only partially relevant to nature/nurture; it has more to do
with the problems of conducting cross-cultural studies.
A final problem with investigating the nature/nurture debate is that humans learn
very quickly and so, if we want to find out if behaviour is inherited, we should test
people when they are very young. The children in the Bandura study were about
3-4 years old, and so had plenty of time to learn to be aggressive. It would have
been better, but unethical, for Bandura to have used small babies to see if they
were aggressive.
Washoe was caught in the wild when nearly a year old – perhaps a better example.
Your answers:
 Separating out nature and nurture
 difficult to design a culture-free test
 You have to start with a new-born animal or human to ensure that you
control the nurture side – Washoe (Unethical – especially with human
babies)
 Building nurture onto nature – washoe used his arms
Nature Nurture debate
Nature refers to inherited characteristics and nurture is the product of experience
(environmental influences and learning). The philosopher John Locke claimed that at
birth we are like a blank slate. We inherit nothing and all behaviour is acquired as a
consequence of experience.
Nature and nurture interact rather than one or the other determining behaviour. The
distinction made between genotype (inherited potential behaviour) and phenotype
(observable behaviour) shows us that we can never actually access the genotype and
therefore are always assessing nature and nurture jointly. For example, Nature—
nurture influences are often researched using twin studies, and comparing
monozygotic (identical) and dizygotic (non-identical) twins. However, we now realise
that monozygotic twins are not exactly identical, partly because of small genetic
differences and also because they create their own micro-environments (each child
reacts to others in different ways; what they attend to and who they choose to interact
with). The fact that twins who are reared apart often have similar environments
further confounds the data.
Examples of the nature—nurture
debate in psychology
Perception. To what extent is what we see—for example the perception of depth or
visual illusions—an innate aspect of the physical visual system? Or are some aspects
of perception learned and therefore different in different cultures? (see Deregowski)
Language. To what extent are humans “hardwired” to acquire language, or is their
ability to use language based on exposure and imitation? If the latter is true, then it
should be possible to train nonhuman animals, which don’t have the innate brain
mechanisms, to use language. (see Gardner and Gardner)
Aggression. To what extent is violent behaviour an aspect of a person’s nature, or is it
learned? For example we might propose that men are more aggressive than women
because they are innately more aggressive or it may be that, in our society, men are
taught to respond more aggressively than women (nurture). The question has
important practical applications in the reduction of aggression. If it is down to nature,
then drug therapies may offer the best means of prevention.
(See Bandura)
Gender development. Each individual’s chromosomes determine sex; gender identity
and gender role behaviour are largely moulded by society though there is evidence
that biology may play an important role.
Causes of mental illness. Recent research has found evidence of a genetic basis for
many atypical disorders, however the diathesis-stress model suggests that a person’s
genetic make-up will predispose them to certain disorders but environmental factors
(stresses) actually trigger the expression of the disorder. The more susceptible an
individual is, the fewer stresses are necessary. This means that neither nature nor
nurture individually causes dysfunction. The disorder comes about as a result of the
interaction of nature with nurture. (See Thigpen and Cleckley)
Expressing inheritance
When psychologists explore the extent to which a characteristic is inherited they use a
variety of measures.
The concordance rate expresses the extent to which two measures are in
agreement. For example, if 20 twin pairs are studied and in 18 of them both had
developed schizophrenia, this would produce a concordance rate of 18/20 or 90%,
which is very high concordance. Alternatively one can correlate the IQ scores of two
individuals, and the degree of correlation shows us how concordant they are.
Monozygotic (identical twins) have the same genes (100% concordance) whereas
dizygotic (non-identical) twins and siblings are genetically 50% similar.
Where do the main approaches in psychology stand
on nature—nurture?
The biological approach by definition takes a nature position.
The behaviourist approach is entirely on the side of nurture, though the potential for
learning is innate.
The cognitive approach similarly makes no special claims for nature except in so far
as the structure of the mental system is innate. Its development, however, is a
response to experience.
The psychoanalytic approach combines both nature and nurture in the view that
innate, sexual forces are modified by experience to produce adult personality.
The evolutionary approach is clearly nativist (nature).
The humanistic approach emphasises nurture but holds certain views about the nature
of humankind—that it is positive, inclined towards psychological good health, and
has the potential for self-actualisation.
The social constructionist approach is an example of the nurture approach. Social
forces shape us.
Acknowledgements
Michael W.Eysenck & Cara Flanagan, 2001, Psychology for A2 level,
Psychology Press, ISBN 1-84169-251-4 (Highly recommended text for broad
overview of psychology, written in an easy to understand style)