Criminal psychology - Topic 1&2

Topic 1 - What makes a criminal

Physiological and non physiological explanations

Raine et al

Biological strategies for preventing criminal behaviour

BR - Lombroso

Individuals have evolved to possess certain criminal features

Criminals are a subspecies of humans identified by features such as; large ears, defined jawline, narrow sloping brow or physical abnormalities

BR - Sheldon

Criminal body types

Identified three body types; ectomorphs, mesomorphs and endomorphs

Through looking at common body types amongst inmate populations, concluded mesomorphs were most likely

They have a more muscular build - may prejudice others to treat them like criminals or may recognise that they can gain rewards through force

BR - Jacobs

Men born with the genetic abnormality of XYY were more aggressive (0.001% of pop but 1.5% of criminals)

Research showed that having biological parents with convictions increases your chance of having a record

However same can be said for adoptive parents

BR - Bandura and SLT

You know herrrr

Trzesniewski - Self esteem

Adolescents with low self esteem were more likely to engage in criminal activity

Linked to humanist explanation as those individuals have failed to reach self actualisation due to no access to self esteem sources

BR - Self fulfilling prophecy

Jahoda - Found that in some cultures children are assigned soul names depending on which day of the week they were born

In ashami cultures, boys born on a wednesday (22%) are thought to be aggressive and violent whereas monday boys (7% of crime) were calm

Labels result in mistreatment which leads to criminal activity

Raine - Aim

To study brain activity in murderers and non murderers using PET to find out if there were differences in areas associated with violent behaviour

Raine - Sample

EG - 41 murderers (39m, 2f) with a mean age of 34.3yrs

Each had been charged with murder/manslaughter and pleaded NGRI

Control - Matched for sex and age, and for six participants, schizophrenia

No ppts took any medication for 2 weeks prior

Raine - Design

Quasi experiment

Matched ppts design

Raine - Procedure

30 seconds before ppts completed a CPT, they were injected with a glucose tracer for a PET scan (insuring that the novelty of the task wasnt a factor)

They were allowed to practice the CPT beforehand

CPT continued for 32 minutes, PET images of 10 horizontal slices were taken and analysed using techniques

Raine - Techniques

Cortical peel - used for lateral areas such as areas of the temporal lobes

Box - used for medial areas such as the superior frontal gyrus

Raine - Results

Murderers had significantly less activity in the corpus collosum (0.56 compared to 0.68)

They had abnormally asymmetrical activation in areas of the limbic system

Raine - Conclusions

Areas found to have abnormal activity were associated with aggressive behaviour, a lack of fear and problems with controlling and expressing emotions (amygdala) +++

Also associated with learning conditioned emotional responses and effects on areas associated with learning could lower IQ

Strategy A - Plastic surgery for prisoners

Reconstructive face surgery to alter the appearance of criminals to make them look more ‘normal’ reducing bias from the public

Lewinson - study where 450 reconstructions were given in a prison population

the effect was improved self esteem, improved motivation and increased co-operation with guards

reoffending rates fell to 42% as opposed to 74% of the general prison population

Strategy A - Implementation

The government could implement optional facial surgery for prisoners with prominent facial features e.g. facial scars/deformities

Strategy B - Chemical castration

Involves providing oestrogen supplements to males to counterbalance their testosterone levels and thereby reduce aggression which is a key component in violent crimes

Jacobs found that those with the XYY chromosome are more likely to be aggressive prisoners and show increased levels of testosterone

Strategy B - Implementation

Convicts who have been charged with violent/sexual crimes could be made to undergo chemical castration as part of their sentence/ the conditions of their release

This could lower the reoffending rates

Topic 2 - The collection and processing of forensic evidence

Motivating factors and bias within processing forensic evidence

Hall and Player

Strategies for reducing bias

Charlton et al

Interviewed 13 fingerprint analysts and produced a description of their main motives

These were summarised as; rewards, hope and satisfaction related to catching criminals, factors linked to case importance, feeling associated with finding matches and the need for closure along with fear of mistakes

Dror (2011)

Found that individual fingerprint analysts differed both from one another (inter-rater reliability) and from themselves over time (external reliability)

One reason for this is the range of cognitive factors that can bias decisions

Dror (2005)

Showed that, when decisions are being made about fingerprint marks, a high emotion context increases the likelihood of a match being made with an ambiguous pair

University students were given a pair of fingerprints in relation to different crimes (emotional - murder) (non-emotional - theft) and had to decide whether they matched, the context created a bias in ppts decision making

Hall and Player aim

To investigate whether fingerprint experts were emotionally affected by case details in the report and whether emotional context would bias their judgement

Hall and Player sample

70 fingerprint analysts working for the metropolitan police fingerprint bureau with experience ranging from 3 months to 30yrs

All were volunteers who responded to a request to take part

Hall and Player design

Lab experiment with an independent measures design

Hall and Player procedure p1

A finger mark from a known source was superimposed onto an image of a £50 note with most of the ridge detail obscured, meaning the latent mark was only just identifiable

It was confirmed by experts that the print was of poor quality and an ambiguous match to a set of 10 prints

The colour, size and detail were typical of the quality usually seen

Hall and Player procedure p2

Each ppt given an envelope containing a test mark card, the 10 print fingerprint and the examiners report (with either high or low emotional context), this stage replicated the verification stage of identification

Participants were randomly assigned to groups of 8 and asked to treat the experiment like a normal day

Hall and Player results

50% of those that read the high emotional context felt affected, compared to 6%

The decisions made by the experts are very similar for the two emotional contexts

Hall and Player conclusions

Emotional context does not affect analysts final decisions on fingerprint comparison

Strategy A - Independent analysis

Suggests the latent print should be analysed first in isolation rather than alongside the comparison mark

If analysts compare first, they found fewer key elements of the print

Dror suggests that the comparison creates cognitive expectations which reduces the attention of the analysts to only look at similar features

Strategy A implementation

Analysts should follow a linear approach as suggested by Kassin

1. Analyse the latent print in isolation

2. Analyse the comparison print in isolation

3. The two sets of prints should be compared to allow analyst to reconsider their original analysis of inconclusive features of latent print

Strategy B - Working in isolation of other evidence

Analysts should be unaware of any other crime scene information such as the nature of the crime to avoid emotional context impacting their decisions

Analysts who verify the decision should not be aware of the original judgement

Use Hall and Player as evidence (although it did not impact their accuracy, it did impact their cognitive state so this should be avoided to minimise external input)