Biological approach Flashcards
Define the biological approach.
Explains human behavior through biological factors; genes, neuroanatomy, neurochemistry, and evolution
What are the 3 key assumptions?
-Psychological characteristics are first biological so have biological root causes
-Look at biological structures and processes in the body to understand behavior
-The mind lives in the brain, all thoughts, feelings, and behavior have a physical basis
What is the genetic basis of behavior?
give an example
That behavioural characteristics are inherited in the same way physical characteristics are
eg, sert gene linked to OCD
What are concordance rates?
% of shared characteristics
What are monozygotic twins?
and what percentage of DNA do they share
Identical twins with one zygote
Share 100% DNA
What are dizygotic twins?
and what percentage of DNA do they share
Non-identical twins with 2 zygotes
Share 50% DNA
How are the twin studies used to investigate the genetic basis of behavior?
-Conc rates are calculated between twins for the probability that they share the same disease
-68% of monozygotic twins will have both have ocd if one does
31% of dizygotic twins will have both have ocd if one does
Give a specific example of a twin study that has shown that genetics play a role in behavior
Criminal beh -Christiansen 1977
-looked at concordance rates for criminal behavior
-separated by gender
What are the results of Christiansen’s 1977 study?
what does it show
Males: MZ,35% - DZ,13%
Females: MZ, 21% - DZ,8%
-Genetics are partially responsible for our behavior as concordance rates are higher in MZ than DZ
-Shows nurture plays a role as the results aren’t 100 percent for the MZ twins or 50 percent for the DZ twins
What is a genotype?
The actual genes a person possesses
What is a phenotype?
The observable characteristics of an individual based on the expression of their genes.
What is neuroanatomy?
How different brain structures affect our behavior.
Different areas are responsible for different behaviors
What does neuroanatomy use?
Brain scanning techniques like FMRI
What are the 2 examples of neuroanatomy?
Language- Broca’s area responsible for speech production
Wernick area controls comprehension of speech
OCD- abnormal functioning of frontal lobes, linked to hoarding disorder
(deficits in decision-making)
What case study is used for neuroanatomy?
Phineas Gage
How does the case study of Phineas Gage support the role of neuroanatomy on behavior?
-Rod through frontal lobes
-Post recovery, personality change
-Was hardworking now a drinker and doesnt like to socialize
-Had damage on left pre-frontal cortices
-they’re responsible for decision-making and emotional regulation
BUT may not support as he may have had personality change from PTSD
What is neurochemistry?
Study of how brain chemicals influence behavior
What’s another word for brain chemicals?
Neurotransmitters
What is linked to many mental disorders?
Abnormal functioning of neurotransmitters
How does neurochemistry link to a specific psychological disorder? (2)
High dopamine leads to schizophrenia
Low serotonin leads to depression
Define evolution
Changes in characteristics that are inherited over several generations
Describe darwins theory of natural selection
genetic mutations that are beneficial to survival are passed on through reproduction
Give memory as an example of evolution (4 mark)
1- natural selection explains why evolution occurs
2- memory will be randomly mutated in individual, enabling them to remember the best food source better than their peers
3-they have an adaptive advantage to survive and pass on
4-Over time all will have better memory as the ones who don’t will die and cannot pass on genes
Describe the evolution of phobias
1- persons scared of something dangerous
2- run away to survive (adaptive advantage)
3- will survive and pass on the adaptive advantage of being scared
4- overtime passes on genes that people scared of things
What is an adaptive advantage?
Something that increases the chance of survival over the competition to reproduce
What are 2 strengths of the biological approach?
- scientific
- real-life application
What are 2 limitations of the biological approach?
reductionist.
deterministic
How is the biological approach scientific? and why is this a strength
Because it uses precise scientific methods like scanning techniques and twin studies. This increases the internal validity (accuracy)
How can the biological approach be practically applied?
treatments for those suffering from (eg SSRIs increase serotonin levels for depression)
How is the biological approach deterministic? and how is this a limitation
(happens in one way)
Biological determinism, all behavior is determined by psychological factors and genetics. Individuals can’t be held responsible for actions
How is the biological approach a reductionist approach?
All human behavior is explained through biological factors only and it ignores all other factors such as emotions
What is the difficulty with using twin studies to evidence a genetic basis of behavior?
-confounding variables, MZ twins share 100% DNA so they share the same nature but the results may also be from sharing the same upbringing (nurture) especially if they’re the same gender
-the only way to be able to get accurate results is by separating Mz twins at birth so they have different upbringings but this is unethical.
What is the issue of cause and effect in the biological approach? explain its importance
We cannot assume brain abnormality is a direct cause of mental illness as abnormality may have developed as an effect of an illness, so it is not very useful if we cannot establish cause and effect.
