Topic 3 - Biological approach to Psychology (Introduction) Flashcards
What are the 3 assumptions of the Biological Approach?
- The genes which a person possesses influences their behaviour.
This means that behaviour evolves in the same way as physical
characteristics. - The brain is the main focus, since this is the origin of how the
world is seen and acted upon. - Neurotransmitters and hormones are responsible for the body’s
chemical processes and are related to a person’s behaviour
because they influence their response to the environment.
What is the Biological Approach?
The biological approach sees behaviour as rooted in the
physiology and biology of the body
What is a genotype and what is a phenotype?
A person’s genotype is their genetic make-up, inherited at
conception, which carries the information about their
characteristics and is unique to every individual, unless they are
one of a pair of identical twins.
The phenotype on the other hand
describes the actual characteristics which are expressed when the
genotype interacts with the environment.
What has work carried on twins highlighted?
Work carried out on twins has highlighted the role of genes versus
the environment in producing certain behaviours.
What are the two different types of twins?
- Monozygotic-
Identical twins (termed monozygotic because they were produced by
one zygote which divided early in development).
- Dizygotic-
Non-identical twins (termed dizygotic because they were produced by
two egg cells and two sperms creating two individual zygotes).
What proves there is a high likelihood that there is a
significant genetic component to a behaviour?
If monozygotic twins show a more similar set of behaviours than
dizygotic twins then there is a high likelihood that there is a
significant genetic component to that behaviour.
How do we express this similarity and what does a 100% mea?
To express this
similarity we use a statistic called ‘concordance rate’.
A
concordance of 100% means that the twins have the same
behaviour.
What are 3 types of Concordance Research?
Schizophrenia: Gottesman (1991)- MZ Twins (48%) DZ Twins (17%)
Bipolar Disorder: Craddock and Jones (1999) MZ (40%) DZ (5-10%)
Anorexia Nervosa: Walkers and Kedler (1995) MZ (23%) DZ (9%)
What shows there is an environmental output?
It is also significant that the rate for MZ twins is not 100 per cent in any of these pieces of research. This suggests that, although there may be a genetic influence, it is not the sole reason for the behaviour/disorder occurring. If it was entirely due to genes you would expect the concordance rate for identical twins to be 100 per cent as they are 100 per cent genetically similar. It seems that some behaviours could be a mix of both genetics and environment.
How does evolution operate and what does it result in?
Evolution operates through mutations in the genetic code, resulting
in characteristics that impose a survival factor on the individual. If
the characteristic is advantageous, the individual is more likely to
survive, breed and successfully raise offspring. If these offspring
have inherited the advantageous form of the genes, then they
again are more likely to survive and so on.
Can you give the example of aggression as a survival factor?
Take the example of aggression. An animal that displays aggression
increases its survival rate by increasing its access to resources such
as food and mates. In defending a territory it acquires for itself a
place to gain food and to raise its young safely. Displays of
aggression will also attract a mate and give it a firm place high up in
the hierarchy. If the features that make the animal aggressive are
genetic they will be inherited and the aggressive behaviour will be
passed on down the generations.
What do Biopsychocologists suggest?
Biopsychologists suggest behaviour can be inherited in the
same way as that of physical characteristics.
How is it different from the learning approach?
(Note the very different explanation given here from the learning
approach, which said that animals are born a ‘blank slate’ and that
behaviour is learnt through observation and copying or through
trial and error.)
What is evidence for the gene for aggression?
There is now evidence of a gene for aggression and the expression
of this via the chemical monoamine oxidase A.
