3.1- evaluating biological theories Flashcards
Mednick- Adoption
1) strength
adoption studies overcome the problem faced by twin studies. As identical twins are brought up in the same household making it impossible to separate out the influence of genes and the environment.
the research design is logical- allows us to see the importance of “nature” versus nurture”
provides further support to genetic explanations- shows adoptes who’s biological parents have criminal records are more likely to be criminal
Mednick- adoption
2) weaknesses
. Many children are not adopted immediately but remain with their biological family for some time. This early environment may be the true cause of criminality.
. adopted children are often placed in environments similar to their birth family. (same class/ethnicity). similar environments may produce similar behaviour.
Twin studies
1) strengths
. because MZ twins are genetically identical- it is logical to examine whether offending behaviour is also identical.
.give support to genetic explanations- Christian found higher concordance rates of criminality in MZ than DZ.
Twin studies
2) limitations
. If genes are the only cause of criminality the CR of MZ twins would be 100%. But studies found only half or less
. Parents treat identical twins more similar than non-identical twins . Identical twins may also feel closer. These factors may cause similarity in behaviour.
.
XYY syndrome
1) strength
. Jacob found an association between XYY and offenders prisoned for violent behaviour.
XYY
2) weakness
Not all men with XYY commit crime or act aggressively.
. Theory can’t explain all men who show aggression or commit crime. Also can’t explain female criminality as its only a gene found in men.
.The theory ignores environmental factors i.e. upbringing. Having XYY can make you appear different which could lead to bullying or marginalization.
Brain injuries and disorders
strength
. Prisoners are more likely than non prisoners to have brain injury
. brain injury or disease has lead to major changes in a persons personality and behaviour. Including criminality
Brain injuries and disorders
limitation
. crime caused by brain injury or disease are rare. The sufferers original personality is more important whether they engage in crime
biochmeical
strength
testosterone levels and male offending both peak around the same age- suggesting hormones affect criminal behaviour.
. sexual hormones, blood sugar levels, and substance abuse can affect mood, judgement and aggression.
biochemical
weakness
. biochemical processes may predispose some individuals to offend- but it may require an environmental trigger to cause offending.
lombroso activistic form
physiological theory
strength -
. He was the first person to study crime scientifically-using objective measurements to gather evidence. Previously crime was seen as a moral or religious issue.
.By arguing that offenders were not freely choosing to commit crime, he helped us to focus on how we might prevent further offending rather than simply punishing offenders.
Lombroso activistic form
physiological theory
weakness-
. Research since has failed to show a link between facial features and criminality
. He did not compare his findings with a control group of non criminals. Maybe he would of found similar characteristics among the general population.
Racist- calls the “primitive savages associating them with non-western societies.
sheldon- somatotypes
strength-
. other studies have replicated sheldons findings, findings that 60% of the offenders were mesomorphs
. the most serious criminals in sheldons sample had the most extreme mesomorphic body shape
Sheldon- somatoypes
weaknesses
Correlation not causation= . Criminal may develop a mesomorphic build as a result of needing to physically tough to succeed.
Sheldon doesnt account for endomporphs and ectomorphs who do commit crime.
social class may be the true cause both of offending and mesomorphy. Convicted offenders are mainly working class- who are more likely to have manual jobs were they require an athletic build.
