L7 - The Biological Approach - The Influence Of Genes & Evolution On Behaviour

Question 1

Genetics - 3 facts

Answer 1

• everyone has 23 chromosomes and 10000 genes
• each chromosome is made of DNA —> consists of genes
• genetics involves passing characteristics and key information from 1 generation to the next

Question 2

Genetics definition

Answer 2

The extent to which a psychological characteristic is determined by genes/enviroment

Question 3

Genotype definition

Answer 3

• the genetic code written in DNA of individual cells - inherited from biological parents
• consists of genes a person possesses & can be dominant or recessive

Question 4

Phenotype

Answer 4

Characteristics of an individual —> determined by expression of physical behavioural & psychological traits
Genotype + environmental factors = phenotype

Question 5

Genetics

Answer 5

• Individuals might inherit certain characteristics which are carried on genes (on chromosomes)
• Psychologists research genetics by studying twins (MZ monozygotic identical twins, or DZ dizygotic non identical twins).
• Twin studies allow psychologists to look at concordance rates between twins (the chances of both twins inheriting a certain trait e.g. depression or intelligence)
• 60-80% of intelligence is thought to be genetic!
• from using gene mapping, it has been found that chromosome 13 carries the gene for schizophrenia, and chromosome 11 carries the gene for bipolar depression.

Question 6

Genetics evaluation

Answer 6

strengths
- scientific
- twin & adoption studies
- can screen people
weaknesses
- reductionist
- ignores other approaches

Question 7

Scientific

Answer 7

An advantage of examining genes and the role they have on behaviour is that gene mapping can help psychologists locate genes on chromosomes which is highly scientific and objective. Therefore investigating genes involves precise methods of investigation which would be supported by science

Question 8

Twin & adoption studies

Answer 8

An advantage of studying genetics is that it often involves using twin and adoption studies. This is very useful when examining MZ (monozygotic twins) who are identical as it can help psychologists examine concordance rates in relation to behaviour. The research by Gottesman and Shields would support the idea that certain illnesses such as schizophrenia are transmitted genetically

Question 9

Can screen people

Answer 9

Genetics has the advantage in that it can help psychologists screen people to see if they carry genes for certain illnesses. This would involve gene mapping and it can help psychologists identify individuals who might be at risk from certain illnesses or diseases such as depression or some forms of cancer. This means that people might get psychological help before they become unwell (preventative)

Question 10

Reductionist

Answer 10

A disadvantage when examining the role of genetics is that it is reductionist. It takes a complex human behaviour such as IQ and reduces it down to small components alone such as genes. This idea seems inaccurate, as IQ is not solely dependent on genes; other factors need to be considered such as the environment

Question 11

Ignores other approaches

Answer 11

The role of genes and its effect on behaviour and be criticised, because other models and approaches in Psychology are being ignored. For example the cognitive and behavioural approaches would also need to be considered when examining behaviour. An example is that someone who has depression might carry the gene for depression, but they might also have faulty and negative cognitions which have been ignored.

Question 12

Genetic study

Answer 12

Role of genes in developing schizophrenia - twin studies - Grottesman & Shields

Question 13

Grottesman & Shields

Answer 13

• Gottesman and Shields investigated 224 sets of twins from 1948-1993 who appeared on the Maudsley twin register (106 sets MZ & 118 DZ)
• The average age of the partciparts was 46 years of age and re priapart from range ethnically.
• conducted in a London hospital, longitudinal study over a period of 25 years.
• study relied on the fact that one twin already had the illness of schizophrenia, and concordance rates were investigated; which examined the likelihood or the chances of the healthy twin becoming schizophrenic over time.
• They used: Doctors case note, The DSM & in depth interviews
• 48% of MZ twins were both concordant for schizophrenia by the end of study
• 17% of DZ twins were both concordant for schizophrenia by the end of study
• shows MZ twins were more likely to develop schizophrenia compared to DZ if 1 twin had it, due to the fact they had same genetic material (more likely to be concordant) - suggests it’s genetic

Question 14

Evaluation of Grottesman & Shields

Answer 14

strengths
- longitudinal
- supports biological approach
weaknesses
- ignores behavioural approach
- relied on patient interviews

Question 15

Longitudinal study

Answer 15

A strength of Gottesman and Shields study is that it was longitudinal. This means that the schizophrenic patients could be tracked over long periods of time in order to monitor the development of the illness schizophrenia. This means that longitudinal studies are very valuable when investigating whether schizophrenia is caused by genetics

Question 16

Supports biological approach

Answer 16

The research by Gottesman and Shields supports the biological (genetics) approach as the results show 48% concordance rates for schizophrenia in MZ twins and 17% concordance in DZ twins. Therefore the results support the biological argument that schizophrenia can be transmitted by genetics

Question 17

Ignores behavioural approach

Answer 17

The research by Gottesman and Shields ignores the behavioural approach when examining the causes of schizophrenia. Identical twins often copy and model each other’s behaviour, so it could be that the healthy twin has modelled or copied schizophrenic behaviour rather than getting the illness via genetics. Therefore we must investigate fully whether the healthy twin gained schizophrenia via genetics or from observing and copying behaviour

Question 18

Relied on patient interviews

Answer 18

research conducted by Gottesman and Shields could be criticised because it relied on interviews with patients. Schizophrenia patients often have difficulty with their speech and communication and therefore some patients might have found it difficult to communicate their symptoms effectively to the psychologists/psychiatrists. Therefore this issue could have had a negative effect on the diagnosis and classification of schizophrenia

Question 19

What are concordance rates

Answer 19

• statistical measure that shows the proportion of pairs that share a trait given that one already possesses the trait

Question 20

What is gene mapping

Answer 20

Describes the methods/processes of determining the location of a gene on a chromosome & the difference between the genes

Question 21

MZ vs DZ twins

Answer 21

MZ - monozygotic - identical (one egg cell) - same genetic material
DZ - Dizygotic - non-identical (two egg cell) - 50% same genetic material

Question 22

What’s the DSM

Answer 22

• diagnostic statistical manual of mental health - used in psychology to classify psychological disorders

Question 23

Evolution

Answer 23

• Darwin (1851) focused on natural selection and adaptiveness to the environment over time
• The genetic makeup of an individual can undergo a random change/mutation due to a factor in the environment, can lead to a characteristic change in future generations of offspring, may mean that survival & chances of reproduction are greater, and so mutated gene will is passed on and is adaptive
• Physical characteristics of a species may vary, and it might partly be due to genetics and inherited characteristics, but we must also acknowledge the environment
• Adaptiveness is important, because individuals often compete with each other for resources, and those who survive will reproduce (survival of the fittest).

Question 24

Evolution cont.

Answer 24

• Lea (2005) has found that aggression might be genetic, The warrior gene (MAOA gene - Monoamine Oxidase A) is found within the genotype of 33% of males
• Could mean that the most aggressive males have more chance of survival and passing on their genes - The research is ongoing into this topic.
• In the animal kingdom, evolution can be seen in the giraffe and their long necks. Over time, giraffes evolved and their more necks got longer so that they could access the best leaves in the tree for food and nutrition. This means that the shorter limply giraffes had less chance of accessing the highest leaves, and therefore they might have had poor feeding and survival
  The giraffes with the shortest necks might have died out and not evolved.

Question 25

Why might agression be adaptive

Answer 25

• if aggressive more likely to fight for food & resources, so more likely to survive & reproduce

Question 26

Evaluation of evolutionary approach

Answer 26

strengths
- supported by nature side
- supported by Darwin
- species compete
weaknesses
- doesn’t clearly explain some behaviours
- doesn’t consider cognitive/behavioural explanations

Question 27

Supported by nature side

Answer 27

Evolutionary ideas can be supported by the nature side of the nature and nurture debate. The evolutionary approach states that our biology (genetic makeup) and interactions with the environment have a direct effect on our behaviour, for instance genetic mutations of genes in giraffes have led to them having very long necks so that they can get enough food in the environment and reach the top leaves from the tree.

Question 28

Supported by Darwin

Answer 28

The evolutionary approach is heavily supported by the work from Charles Darwin and survival of the fittest. This can help explain how certain traits become adaptive within a species such as males being very tall, or giraffes having long necks

Question 29

species compete

Answer 29

Evolutionary ideas have their advantages because it means that species will compete with each other in order to seek the best mate to reproduce with. This helps to maximize the chances of healthy offspring being produced who will be healthy and will be able to pass on their genes to the next generation. This helps human/animal species to evolve and adapt

Question 30

Doesn’t clearly explain some behaviours

Answer 30

problem of the idea of evolution is that is does not clearly explain some behaviours and how or why they might be adaptive. For instance OCD has been found to be genetic, but it is not clear how OCD can be adaptive and can help aid survival of the fittest. This is not very clear and is not well explained.

Question 31

Doesn’t consider behavioural & cognitive explanations

Answer 31

The idea of evolution can be criticised because it fails to take into account behavioural and cognitive explanations for behaviour. The idea of every species wishing to reproduce and aid survival seems to take away the idea of free will and cognitions, whereby not all members of a species have this drive or will make such decisions.

Question 32

Evolutionary approach study

Answer 32

Sexual selection by Buss (1989)

Question 33

Buss (1989)

Answer 33

• Investigated what males and females looked for in a long term partner
• 10,000 participants used across 37 cultures
• They had to rate 18 characteristics (physical attraction, finances etc.) using a 4 point rating scale, where 0 = irrelevant, and 3 = indispensable (highly rated).
• The findings showed that females desired males with good financial prospects, resources and ambition
• Males desired females who had reproductive value and were fertile, and all males universally wanted females who were youthful and younger than them
• research conducted by buss seems to support evolutionary explanations for partner preferences

Question 34

Evaluation of Buss (1989)

Answer 34

strengths
- cross-cultural validity
weaknesses
- research findings criticises
- doesn’t consider social & cultural perspectives

Question 35

Research findings critisises

Answer 35

Research conducted by Buller (2005) has criticised Buss’s research findings and the evolutionary explanation. Buller has questioned the idea that females universally prefer high status males with resources. Many females in today’s contemporary society are independent and have their own resources, and therefore do not rely on a mate to financially provide for them.

Question 36

Cross-cultural validity

Answer 36

research conducted by Buss has cross cultural validity when examining evolutionary explanations of behaviour. 37 cultures were assessed and it seems that from an evolutionary perspective females want to be “protected” and “cared for” by their male partner in terms of resources. This is supported by the fact that females might believe that a man with resources can look after her and their future offspring, this helps aid stability for the family unit

Question 37

Doesn’t consider social & cultural perspectives

Answer 37

The research can be criticised because it does not take into account social and cultural perspectives that might affect partner choice. An example is that if males desire younger fertile women, they might feel pressure from their culture and peers to choose a suitable mate that fits in with the “ideal” standard proposed by society. Therefore the evolutionary approach would ignore other factors that might influence mate choice according to society’s norms, values and ideals. An example is that of female body image. Western cultures seem to value a slim or hourglass female body shape whereas some eastern cultures prefer larger and curvy female body shapes