Forensic Psychology Flashcards
Offender profiling
The aim of profiling is to create an idea of the offenders likely characteristics. This helps the police to focus their resources on more likely suspects, and can create new leads within an investigation
The American ‘top-down’ approach
The FBI began by interviewing 36 convicted killers and sex murderers to gain an insight into their thinking and behaviour. They were classified into groups of organised and disorganised. These are used to compare info from new crime scenes to make judgements based on past. However it is based on self-report interviews and a restricted sample, a,so lacks validity and cannot be generalised to wider world
Organised offenders
They were intelligent, socially and sexually competent, lived with somebody and planned their attacks
Disorganised offenders
Less intelligent, socially and sexually incompetent, were more on the lonely side and tend to behave impulsively without planning attacks in advance
The British ‘bottom-up’ approach
Applies psychological research and theories to criminal investigations. Geographical profiling which sees the crime scene as a source of into, the behaviour of the offender would reveal information about their everyday life and characteristics. Also analysed behaviour of convicted offenders
Four main stages when building a profile (FBI)
Assimilating data- collecting all info available at scene and from victim.
Classifying the crime- identifying type of crime committed.
Reconstructing- involves behaviour of both offender and victim
Profiling- making judgements about possible physical characteristics and lifestyle of offender
5 main characteristics involved in geographical profiling
Personal characteristics
Criminal history
Residential location- circle theory
Domestic and social characteristics
Occupational and educational history
Faults of offender profiling
Can only be used for a limited number of crimes such as murders or rapes. Can be used to identify stalkers or arsonists but cannot identify crimes for material gain like theft. Profiling cannot identify a specific person, more so a type of person. Holmes (1989) found profiling to causes arrest in 17% of 88 arrests in 192 cases (ineffective).
Uses of profiling in the real world
Rachel Nickell murder case where they convicted the wrong person with no physical forensic evidence. Case study of John Duffy where they created a profile extremely similar to Duffy’s actual circumstances and characteristics
Positivist criminology
Positivist criminology says that criminal behaviour results from physical or psychological features- no free will is involved
Lombroso (1835-1909): physical characteristics and crime
Studied for common physical characteristics among criminals. Concluded that they were more likely to have atavistic (primitive) features, strong jaw and heavy brow. Other features included dropping eyelids, large ears, lobeless ears, high defined cheekbones, flat nose. Lombroso believed that criminal behaviour came from primitive instincts which survived evolutionary process - genetic ‘throwback’.
Pros and Cons of Lombroso
Highlighted the role of biology in criminology. Considered the interaction between biological, psychological and social factors.
Didn’t use a non-criminal control group to test if features were unique to criminals. Lots of samples had psychological disorders or chromosomal abnormalities which may have been a factor in their crime
Genetic factors of criminality
Some adoption studies have shown higher concordance rates of criminal activity between adopted children and their biological parents, there is a genetic link but there are also other factors. Some psychologists believe that aggression can lead to offending behaviour, studies have shown a link between genes and aggression. A higher percentage of prisoners compared to the world showed an extra Y chromosome XYY which adds more testosterone and violence. However further studies suggested that those with such an abnormality are more likely to be hyperactive, impulsive and lower IQ which can explain criminality
Raine et al (1997)
Investigated a link between brain dysfunction and criminality. Used PET scans to create 3D images of the functional processes happening in the brains of 41 murderers (pleading not guilty by insanity) and 41 control pptts. The murderers showed reduced glucose metabolism in the prefrontal cortex and corpus callosum and asymmetrical activity in the two hemispheres. So some processes were dysfunctional which supported the link. The researcher used a control group matched on age and sex. But researchers could not randomly allocate pptts to control or killers groups so need to be cautious when drawing conclusions about casual relationships
Strengths of the Biological explanation for criminal behaviour
A number of studies have provided support to suggest there is some contribution from biological factors. The biological theories can often be tested scientifically, making them more reliable.
Weaknesses of the Biological explanation for criminal behaviour
No study has shown a 100% concordance rate between MZ twins or parents and children so there must be other factors. Concordance rates for criminality may not be directly due to genetics, could be a result of inherited emotional instability or mental illness which could indirectly result in offending behaviour. Biological explanations can be too reductionist and deterministic
Eysenck’s criminal behaviour as personality types
Neuroticism stability, Extraversion introversion, psychoticism.
Suggested that individuals have genetic predispositions to a particular personality type, but environmental factors play a role to. Psychoticism was a good predictor of criminal behaviour, Extraversion for young people, neuroticism for older people. Combined biological, social and psychological approaches. However it was developed from studies which involved self-report measures so could lack reliability
Neuroticism-stability
Individuals towards the neurotic end of this personality dimension show traits such as anxiousness and restlessness. Traits at the other end of the scale include reliability and calmness
Extraversion-introversion
Individuals towards the Extraversion end of this personality dimension tend or be sociable, impulsive and assertive. Those at the other end tend to be quiet, passive and reserved