Approaches : The Biological Approach Flashcards
What is the biological approach?
Suggests everything psychological is first biological and studies processes within the body:
• the role of genetics
• neurochemical bases of behaviour
• hormones
The role of Genetics - what are genes?
Genes are the genetic info carried by DNA in chromosomes, found within a cells nucleus and are passed on through generations of a species.
The role of Genetics - what do behavioural genetics study?
Whether behavioural characteristics (intelligence, personality, mental disorders, etc) are inherited the same way as physical characteristics (eye colour, height, etc)
The role of Genetics - twin studies
Used to investigate the extent genes that create a predisposition to certain behaviours are inherited.
The role of Genetics - what are concordance rates?
The extent both twins share the same characteristics
The role of Genetics - Monozygotic (identical) twins
〇ᯡ
↓
⚇
⇙⇘
〇 〇
Shared placenta, higher rate concordance rate for depression, IQ, schizophrenia, etc (suggests a genetic bias)
The role of Genetics - Dizygotic (fraternal) twins
〇ᯡ 〇ᯡ
↓ ↓
⚇ ⚇
↓ ↓
〇 〇
Separate placenta
The role of Genetics - studies and results
Behaviour/ disorder Research MZ twins DZ twins
Schizophrenia Gottesman, 1991 48% 17%
Bipolar depression Craddock & Jones, 1999 40% 5-10%
Anorexia nervosa Walters & Kendler, 1995 23% 9%
No study reports 100% concordance rates for MZ twins.
The role of Genetics - Evolutionary psychologists
Charles Darwin in Origin of Species (1859) described the process of natural selection (undesirable characteristics will die, over gens only adaptive, desirable characteristics remain)
The role of Genetics - what’s a genotype?
Genetic makeup of a person, pairing of alleles for a particular trait (BB, Bb, bb)
The role of Genetics - what’s a phenotype?
The way genes are expressed through observable characteristics (physical, behavioural, psychological) → combined effect of genes + environment
Neurochemical bases of behaviour - what is it?
How levels of neurotransmitters affect behaviour (eg people with low serotonin are more vulnerable to depression). Different parts of the brain are responsible for different functions. Research has shown that in some mental disorders, there are differences in brain structure (eg Chance et al, 2001 found correlation between schizophrenia and enlarged ventricles)
Hormones as a bases of behaviour - what are hormones?
Hormones are chemicals produced by endocrine glands (eg pituitary gland) which make up the endocrine system. The presence of a hormone causes a physical reaction in the target cell, altering its activity. → Carre et al (2006) found increased levels of testosterone whenever a Canadian ice hockey team played in their home stadium - suggesting the hormone energised the players to behave aggressively to defend their home territory
Advs of the biological approach
• it often utilises scientific methods of research to credify psychology as a science. Eg: some research into genetics and neurochemistry requires precise scientific methodology (fMRIS, PET scans, drug trials, EEGs). This makes evidence less susceptible to misinterpretation or examiner bias
• it has many real word applications (understanding ‘abnormal’ behaviour and neurochemical activity has lead to use of psychoactive drugs to treat mental disorders)
Disadvs of the biological approach
• cannot establish causality → often has strongly implied explanations that focus on brain structures. It only tells us if there’s an association between brain structures and behaviour, not that the reduced activity in that area of the brain causes the behaviour or vice versa
• may be considered too biologically deterministic → eg. biological psychologists see behaviour as a result of neurochemical, neuroanatomical or genetic influences which we have no free will to control, however the way genotype is expressed (phenotype) is heavily infuenced by environment, meaning the biological approach doesnt take into account the enviroment and freewill.
• it’s untestable → not possible to show evolution happening therefore isn’t scientific (Darwin critics say) and many agreements are outdated (eg gender)
