A2 Psychology G543 Forensic

Revision cards for the forensic section of G543

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Turning to Crime: Upbringing: Disrupted Families


Sample: 44 children aged 5-16 referred to Bowlby for theft. Compared to 44 cases referred but not thieves.

Method/Procedure: Matched pairs. Conducted interviews with children and parents to learn about early life.

Results: 17 of 44 seperated from mother before the age of 5

Conclusions: maternal deprivation can lead to juvenile delinquency

Notes: extreme cases showed 'affectionless psychopathy' - unable to form bonds with other people

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Turning to Crime: Upbringing: Learning from Others


Theory of differential association

Key points: 

  • Criminal behaviour is learned - mainly in intimate groups
  • Learning criminal behaviour operates on the same principals as other methods of learning

Conclusions: If criminal behaviour is learned, then it can be unlearned

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Turning to Crime: Upbringing: Poverty & Disadvanta


Anomic Paradigm theory

Key points: Innovators are more likely to commit crime as they use illegitimate means of acheiving their goals. 

Conclusions: Poverty forces people to commit crime, as they cannot pay for things like food and bills. Provides a situational argument for upbringing influencing criminal behaviour ie. the situation forces people to commit crime, NOT their upbringing or disposition.

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Turning to Crime: Cognition: Criminal Thinking Pat

Palmer and Hollin

Hostile attribution bias

External attributions - attributes causes to social/environmental factors

Internal attributions - attributes causes of behaviour to self

Neutralisation - neither blaming self or others for behaviour

Sample: 97 convicted male offendors compared to 77 non-offenders, aged 12-24 years (burglary, car theft, joy-riding, assault)

Method/Procedure: given a set of scenarios & asked if people were doing things to be nice, mean or not sure.

Results: Offendors more likely to give hostile responses

Conclusions: Hostile attributions can cause people to act violently or criminally

Notes: People neutralise hostile attributions using techniques (Sykes and Matza, 1957)

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Turning to Crime: Cognition: Moral Development


3 levels, 6 stages in moral development:

1 - pre-morality

2 - conventional morality

3 - post-conventional morality

Sample: Studied 75 USA boys over 12 years between 50's & 60's. Alused used children from UK, Taiwan, Mexico, Turkey & Yucatan

Method/procedure: presented with moral dilemmas such as Heinz dilemma

Results: All children could operate at lower levels at a young age & higher levels when older

Conclusions: Morality develops with age.

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Turning to Crime: Cognition: Social Cognition


Labelling theory

Sample: Boys in Ashanti tribe in West Africa

Method/procedure: Boys were named after the day of the week they were born on. Monday boys were thought to be more placid than Wednesday boys

Results: 22% of violent offences recorded in tribe were commited by Wednesday boys as opposed to Monday (6.9%)

Conclusions: Self-fulfilling prohecies can lead to criminal beahviour


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Turning to Crime: Biology: Brain Dysfunction


Sample: 41 murderers pleading insantiy compared with non murderers

Method/Procedure: used PET scan (injected with glucose and performed task while in scanner) to compare glucose in parts of the brain

Results: Murderers had less activity in the prefrontal cortex, lower activity in left amygdala, and lower acitvity in corpus callosum

Conclusions: lower activity in these parts of the brain could make criminal behaviour more likely


Prefrontal cortex is repsponsible for social awareness and morals

Amygdala is responsible for memory, descision making and emotional reactions

Corpus Callosum is responsible for transmitting information between the hemispheres

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Turning to Crime: Biology: Genes and Serotonin


Sample: 5 males in a family in the Netherlands with a history of violence

Method/Procedure: Data collected from urine samples

Results: abnormality found on X chromosome of gene responsible for MAOA production

Conclusions: too early to draw conclusions, but violence could be linked to genetic default

Notes: MAOA is responsible for regulating serotonin, which affects mood and impulsivity. 

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Turning to Crime: Biology: Gender

Daly and Wilson

Sample: Chigaco neighbourhoods with a lower than average male life expentancy (54.3 years to 77.4 years)

Method/Procedure: Correlation study plotting correlations between police records of homicides, school records and local demographic records

Results: life expenctancy was the best predictor of neighbourhood homicide rates

Conclusions: Young males take more risks when they have a lower life expectancy because they percieve the consequences to be lower and rewards to be higher

Notes: also looked at school truancy (higher with lower life expectancy)

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Making a Case: Interviewing Witnesses: Recreating


Sample: People over 30

Method/Procedure: Used 10 faces of celebrities likely to be unfamiliar to sample, looked at for 1 minute then had to construct composite face 2 days later using different techniques. Other participants then had to name, sort and pick from a lineup the faces 

Results: sketch best for sorting - 54.4, e-fit best for lineup - 60.0

Conclusions: Sketch is probably the best, as another human is interpreting the face and also sees it holisticaly

Notes: Techniques for producing composite faces have since improved, especially EvoFit

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Making a Case: Interviewing Witnesses: Accurate id


Method/Procedure: Participants split into 5 groups, watched a 2 minute video where a receptionist at a hair salon hands a man money. in the different versions he was holding:

1. nothing (control)

2. scissors (high threat, low unusualness)

3. handgun (high threat, high unusualness)

4. wallet (low threat, low unusualness)

5. raw chicken (low threat, high unusalness)

filled out questionnaire 10 mins later, asked to describe receptionist & man and what he was doing, then idefntify him from a lineup

Results: high unusalness got significantly poorer description of target

Conclusions: unusualness conflicts with schema so brain is confused, therefore less concentration on situation or other factors

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Making a Case: Interviewing Witnesses: Cognitive I

Geisleman and Fisher

4 principles of cognitive interview:

1. context dependence - recreating the place or emotional state the witness was in

2. changing order of how they witnessed the event - telling it backwards

3. changing perspectve of the witness - telling it from another angle

4. ask witness to report everything (no matter how insignificant) - free association to jog memory

Method/Procedure: CI compared to Standard interview and hypnosis - watched film and interviewed 48 hours later

Results: CI had highest accurately recalled items (41.2) and marginally higher errors

Conclusions: Cognitive interview is a more effective method of interviewing witnesses, though some errors may occur

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Making a Case: Interviewing Suspects: Detecting Li

Vrij and Mann

Sample: 52 police officers from Netherlands

Method/Procedure: showed 8 video clips of press conferences where families appealed for information, 5 were 'crocodile tears'. Asked if person was lying, how confident they were with the decision, could they understand them, were there any behavioural cues they spotted. 

Results: 3 officers accurate 80% of the time, 49/52 officers doing no better than guessing

Conclusions: Police technquies of detecting lies are not adequate (at least in Netherlands)

Notes: 38 officers tested during a lecture & 14 tested during a coffee break

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Making a Case: Interviewing Suspects: Interrogatio

Inbau's 9 steps

1. Direct positive confrontation - told they are considered to have comitted offence

2. Theme development - given chance to shift blame

3. Handling Denials - suspect not allowed to deny

4. Overcoming objections - ingore reasons for suspect's innocence

5. Procurement & retention of suspect's attention - maintain proximity, eye contact & use first name

6. Handling suspect's passive mood - try to generate remorse

7. Presenting an alternative question - given '2 choice lie' (if confess, not charged)

8. Having suspect only relate details of offence - suspect gives oral confessions

9. Converting oral into written confession - written down to be used in court

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Making a Case: Interviewing Suspects: False Confes


Types of false confession & Reasons they are made

Voluntary: Person admits to offence because they believe they have done it - mental disorders

Coerced-internalised: Person is conviced by police they have done it - when they don't trust memory e.g. head injury or drunk

Coerced-compliant: Confesses to a crime they know they didn't commit - coercive interrogation they wish to get out of

Factors affecting false confessions:

Defendant - vulnerable people more likely to confess

Arrest & Custody - a sudden or night time arrest & long periods of interrogation

Mental & physical state - suspect is anxious, ill, stressed or drunk

Interrogative factors - coercive, biased or leading tactics result in false confessions

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Making a Case: Creating a Profile: Top Down Approa

FBI typologies of murderers and rapists

2 types of murderers: organised & disorganised

4 types of murderers: power-reassurance, power-assertive, anger-retaliatory, anger-excitement

Typologies based on 36 murderers and 41 serial rapists

Used to establish if offences are comitted by the same person, if they will strike again and if the next attack will be more violent

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Making a Case: Creating a Profile: Bottom Up Appro

David Canter

Circle theory

Criminals will use mental maps to determine where to commit crime. They will usually choose an area they are familiar with (for espace routes etc.) and where their presence will not be suspisious. 

Circle theory suggests that by looking at the location of an offender's crimes, their home will be within a 5 mile radius that can be drawn as a circle on a map.

Tested the theory in a study and over 85% of cases lived within the circle

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Making a Case: Creating a Profile: Case Study

John Duffy - The Railway Rapist

Comitted a series of 24 rapes over 4 years along a railway track

Collected information from the victims about the ****** and his actions and analysed them. Canter came up with profile on 28th July 1986:

  • lived in the area near the first 3 rapes
  • lived with a wife/girlfriend, without children
  • mid to late 20's, light hair, 5'9"
  • semi-skilled job not with the public
  • has a few very close male friends
  • sexually experienced
  • previous criminal record

The profile helped identify John Duffy, who had previously been low down on the list of suspects. He fitted 13 of the 17 categories David Canter had identified, and lived in the area he had identified

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Reaching a Verdict: Persuading a Jury: Order of Te

Pennington and Hastie

Sample: 130 students 

Method/Procedure: Lab experiment, mock jury using mock murder trial on tape, 4 conditions:story and witness order (A,B,C,D)

Results: Condition C (defence using story order and prosecution using witness order) returned a 31% guilty verdict, Condition D (defence using witness order and prosecution using story order) returned a 78% guilty 

Conclusions: Story order is more persuasive

Notes: Story order - presenting witnesses in the oder the events occured

Witness order - presenting witnesses in order of importance

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Reaching a Verdict: Persuading a Jury: Persuasion

Hovland and Janis - Yale model of communication

Source: must be credible, knowledgeable and attractive - can be done by discrediting witnesses, quoting facts etc. appearance can be controlled by dressing smartly

Message: has to have some emotional sppeal, but not too much & should account for primacy/recency effect. A two-sided messgae is more effective for a higher educated jury, one-sided for less so (can be controlled by voir dire). Message must be subtle so jury has less resistance to persuasion. Messages are more persuasive in an informal setting - can be done in court setting by joking with Jury and making eye contact.

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Reaching a Verdict: Persuading a Jury: Inadmissabl


Sample: people on jury service (mock jury) At Chicago Law School

Method/Procedure: listened to tapes of a case of a woman injured by a careless male driver

Results: juries awarded $13,000 more to the victim when the evidence that he had insurance was ruled inadmissable

Conclusions: people pay more attention and place more weight on a peice of information when it is ruled inadmissable

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Reaching a Verdict: Witness Appeal: Attractiveness

Castellow et al

Method/Procedure: Mock jury read summary of a case where a 23 year old receptionist accused male employer of sexual harassment. Participants shown photographs of defendant and plaintiff and asked to decide guilty or not guilty.

Results: Attractive plaintiff and unattractive defendant produced 83% guilty, unatrractive plaintiff and attractive defendant 41%.

Conclusions: People make assumptions about a person's motives and character based on their appearance - halo effect

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Reaching a Verdict: Witness Appeal: Witness Confid

Penrod and Cutler

Sample: Undergraduates, eligible and experieced jurors

Method/Procedure: Video of robbery trial where witness stated she was either 80% confident or 100% confident she had identified him correctly. Then asked if he was guilty or not.

Results: 100% confidence returned a 67% guilty verdict, 80% returned 60% guilty verdict

Conclusions: Confidence does not increase witness accuracy, but jurors trust confidence more

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Reaching a Verdict: Witness Appeal: Shields and ch

Ross et al

Sample: 300 students, even split male & female

Method/Procedure: Video of Sexual abuse trial, 3 conditions: evidence in court, evidence behind a protective sheild, evidence via video link, in second study, video stopped after child gave evidence.

Results: Study 1: Type of testimony had no effect on verdict

Study 2: In open court, more convictions than with sheild or video link

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Reaching a Verdict: Reaching a Verdict: Decision M


Method/Procedure: Participants given hypothetical situations and asked to choose the lowest probability that they would consider acceptable for the person in the situation to act.  

Results: Groups chose lower probabilities than individuals, suggesting that risky shift had occured.

Conclusions: Juries might make a risky shift towards a guilty verdict when they are in a group

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Reaching a Verdict: Reaching a Verdict: Majority I


Sample: 123 males, 7-9 participants in each trial sat at a table. only 1 true pariticpant per trial, others were confederates

Method/Procedure: Asked to compare the length of line on different cards. All confederates gave the same incorrect answer on 12 of 18 trials. Participants interviewed about their choice later.

Results: Participants conformed 36% of the time

Conclusions: Majority influence can inflence someone's decision - can influence a jury verdict

Notes: In interviews, participants said they believed the incorret answer or they didn't want to mess up the study. Some didn't realise the extent of their conformity

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Reaching a Verdict: Reaching a Verdict: Minority I


Sample: 172 participants.

Method/Procedure: Shown slides in different shades of blue and asked to state out loud the colour. 2 Conditions: 

Consistent - 2 confederates said green every time

Inconsistent - 2 confederates said green two thirds of the time

Results: Consistent condition had 32% participants report a green slide at least once

Conclusions: A consistent minority can heavily influence a jury 

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