Transcript Haneen`s Presentation

Nature VS Nurture
intelligence
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As you know, we have genes which give us different
characteristics and these genes are inherited from our parents. The
actual genetic code is known as the genotype. However, you get
one gene from each parent for everything, but obviously only one
of these can be expressed; so how the genes actually manifest
themselves is called the phenotype.
Types of studies :
dizygotic
monozygotic
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Looked at MZ twins (since there genetics are the same) who have
been raised together or apart.
found the correlation between intelligences of MZ growing up
together was 0.83 and growing up apart was 0.51. This would
appear to show the environment is more important.
it is only recently that we can prove two twins are identical, it
could be that DZ twins that looked very similar were included
because they thought they were identical.
there is the issue of what was counted as 'separated' in the study,
some twins were included who were raised but different family
members but lived near to each other, regularly saw each other
and went to the same school.
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Adoption studies involve looking at someone who has been adopted and
comparing their intelligence with their biological and adoptive parents.
If the IQ was more similar to their biological parents who have DNA in
common, then we could conclude intelligence was as a result of nature.
if the IQ was more similar to the adoptive parents who have the
upbringing in common, it would be nurture.
Evaluation of these studies:
*The matching of parents. The authorities tend to find adoptive parents
who are
similar to the biological so the transition is easier for the
child. For example, matching up parental occupations.
*Small samples; it is difficult to find people willing to come forward who
also
know their biological parents, this makes the results less
representative.
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involve breeding intelligent parents to see if the offspring are
intelligence.
Because of ethical reasons such studies cannot be carried out on
humans. But in 1940, Tyron conducted a selective breeding study
on rats.
Aim:
Use selective breeding in rats to see
how genetics influences intelligence.
A large number of rats were trained to
run a maze. It was then recorded how
many errors each made.
Method
Conclusion
The best rats at the task were called
maze bright and put together and the rats
poor at the maze were maze dull and they
were also put together to breed
Intelligence is a heritable characteristic
in rats.
The positives of this type of study are that
rats have a rapid life cycle so many
generations will be produced in a relatively
short time and that the vast majority of
DNA in rats and humans are the same.
Evaluation
However the big weakness is that it doesn't
very well relate to humans, since maze
solving does not equate to human
intelligence and that breeding within a
family (as the rats did) is known to very
often cause genetic problems that can
severely impair intelligence
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Both nature and nurture play an important role, however
perhaps that the environment is the deciding factor.
The idea used to describe it is the Rubber Band Hypothesis.
It says that the potential (length of the band) is decided by
genetics. However the environment stretches this band, so
that someone with a low potential could be stretched
beyond someone with a high because of environmental
differences. However if someone with a high and someone
with a lower genetic potential had the same environment,
that person with the higher genetic potential would be able
to 'stretch' their intelligence to a higher level.