Lesson 7 - The Biological Approach Flashcards
Define genetics
The extent to which a psychological characteristic is determined by genes or the environment
Define phenotype
The characteristic of an individual is determined by expression of physical, behavioural and psychological traits
Genotype + environmental factors = phenotype
Define genotype
The genetic code written in the DNA of individual cells - can be dominant or recessive
How do psychologists research genetics
By doing twin studies (monozygotic identical twins, or dizygotic non-identical twins)
What are concordance rates?
The chances of both twins inheriting a certain trait (e.g depression or intelligence)
60-80% of intelligence is thought to be genetic!
What are some positive evaluation points of genetics?
- Gene mapping can help psychologists locate genes on chromosomes which is highly specific and objective, therefore it involves precise methods of investigation which is supported by science
- Studying genetics involves twin and adoption studies. This is useful because it can help psychologists examine concordance rates in relation to behaviour - Gottesman and Shields’ research supports the idea that illnesses such as schizophrenia are transmitted genetically
- They can help psychologists screen people to see if they carry genes for certain illnesses, which involves gene mapping. This can be a preventative measure that allows people to get help before their condition (e.g depression, forms of cancer) worsens
What are some negative evaluation points of genetics?
- It is reductionist, and it reduces a complex idea to small components like genes, which could be inaccurate as IQ is not wholly dependent on genes, instead factors like the environment must be considered
- Other models and approaches are ignored, such as the cognitive and behavioural approach. For example, someone with depression might carry the gene for it, but might also have faulty or negative cognitions which have been ignored
What was Gottesman and Shields’ research into the role of genes in developing schizophrenia?
- Gottesman and Shields investigated 224 sets of twins from 1948-1993 who appeared in the Maudsley twin register (106 were monozygotic, 118 were dizygotic)
- The average age of the participants was 46, and they came from a mix of ethnic backgrounds
- Conducted in a London hospital, the study was a longitudinal study following the participants over 25 years
- The study relied on the fact that one twin already had schizophrenia, and concordance rates were investigated and examined the likelihood of the healthy twin becoming schizophrenic over time
What were the results of Gottesman and Shields’ twin studies experiment?
- 48% of MZ twins were both concordant for schizophrenia by the end of the study
- 17% of DZ twins were both concordance for schizophrenia by the end of the study
They concluded that the chance that both identical twins had schizophrenia was higher than the chance only one had it
What are some positive evaluation points of Gottesman and Shields’ twin studies experiment?
- The study is longitudinal, which means that schizophrenic patients could be tracked over long periods of time in order to monitor the development of schizophrenia. This means that longitudinal studies are very valuable when investigated whether schizophrenia is caused by genetics
- The research by Gottesman and Shields supports the biological approach as the results show that 48% of MZ twins had schizophrenia and 17% concordance in DZ twins. Therefore the results support the biological argument that schizophrenia is transmitted by genetics
What are some negative evaluation points for Gottesman and Shields’ twin studies experiment?
- This research ignores the behavioural approach when examining the causes of schizophrenia. Because identical twins often copy and mimic behaviour, it can be unclear whether they gained schizophrenia through genetics or through observing/copying behaviour
- This research relied on interviews with patients, however sufferers of schizophrenia sometimes struggle with their speech, so as a result they may have found it hard to express their symptoms, negatively effecting the diagnosis and classification of schizophrenia
How does evolution work (give an example)?
The genetic makeup of an individual can undergo a random mutation due to a factor in the environment, and this could lead to a characteristic change occurring in future generations of offspring - if the change means that chances of survival are greater (such as a giraffe with a longer neck reaching tall leaves, whereas short ones cannot) then the mutated gene will be passed on, and the others will die out
What did Lea (2005) discover about evolution?
- He discovered that aggression might be genetic, as the warrior gene (MAOA) is found in 33% of males, meaning that the most aggressive males may have had more chance of survival and passing on these genes to their offspring
What are some positive evaluation points for the Evolutionary approach?
- The evolutionary approach is supported by the nature side of the nature/nurture approach as it states that our genetic makeup and interactions with the environment have a direct effect on our behaviour
- The evolutionary approach is heavily supported by the work of Charles Darwin and the ‘survival of the fittest’ - proves why giraffes have long necks
- Evolutionary ideas are an advantage because it means that species compete to survive, and the fittest and strongest will live to pass genes down to the next generation, helping the species to evolve and adapt
What are some negative evaluation points for the Evolutionary approach?
- The evolutionary approach does not clearly explain some behaviours and how/why they may be adaptive e.g OCD is genetic, but it isn’t clear how it is adaptive
- The idea of evolution fails to take into account behavioural and cognitive explanations for behaviour - the idea that every species wants to reproduce and survive takes away their free will
