Studies: Forensic Psych Flashcards
Aim of Rosenthal and Jacobson
To investigate if teacher expectations could influence children’s intellectual ability
Procedure of Rosenthal and Jacobson
Procedure -
gave elementary students an IQ test
the informed their teachers which children were going to be ‘average’ and which were going to be ‘bloomers’
then came back and conducted another IQ test on the children
Results of Rosenthal and Jacobson
Results -
teachers treated the two groups differently
gave ‘bloomers’ more attention and detailed feed back
children labeled as ‘bloomers’ showed an increase in IQ score that was significantly greater than the ‘average’ group
Conclusion of Rosenthal and Jacobson
Conclusion -
the teachers expectations worked as a ‘self-fulfilling prophecy’
the expectations altered the way the children were treated and thus their academic/intellectual ability
expectations were internalised and become a part of their self-concept and beliefs about themselves
Aim of Loftus and Palmer (study 1)
To show that leading questions distort eyewitness testimonies
Participants of Loftus and Palmer (study 1)
45 American students
opportunity sample
independent groups design
Procedure of Loftus and Palmer
Procedure -
all shown video recording of a car accident
Split into 5 groups
Given a questionnaire about accident
critical question —
‘how fast was the cars going when they ______?’
hit
smashed
collided
contacted
bumped
Results of Loftus and Palmer
Results -
smashed mean estimate score = 40.5 mph
contacted mean estimate score = 32mph
Evaluation of Loftus and Palmer (study 1)
Response bias —
participants may only be responding to the Q’s demands rather than having their memories changed
Participants of Loftus and Palmer (study 2)
-150 American students
Procedure of Loftus and Palmer (study 2)
Procedure -
all shown video of car accident
split into 3 groups
Given a questionnaire about accident
critical question —
‘how fast was the cars going when they ______?’
hit
smashed
no verb
then, came back 2 weeks later
given another questionnaire
critical question:
‘did you see any broken glass?’
(there was no broken glass)
Results of Loftus and Palmer Study 2
Results -
smashed = 32% said yes
hit = 14% said yes
Conclusion of Loftus and Palmer Study 2
leading questions and post event information can influence EWT by forcing the witness to accommodate their schema of the event
responses not due to response bias alone
Evaluation of Loftus and Palmer (Study 2)
Evaluation -
V - high due it being a lab experiment (high control over EVs)
low ecological validity as a video recording of a accident was used rather than a real crime (reduced stress & trauma)
A - high as it highlights the issues with eyewitness testimonies and how leading Qs should be avoided when interviewing witnesses
use cognitive interviews rather than police interviews
Aim of Yuille & Cutshal Study
To examine the effect of leading questions of eye witness accounts of a real event
(as opposed to the numerous lab studies of videoed/ staged events)
Paricipants of Yuile & Cutshal
21 witnesses of a gun-shooting incidence
13/21 agreed to be interviews
10 m, 3 f
ages - 15 - 32
Procedure of Yuile & Cutshal
-21 witnesses interviewed by police immediately after the event.
-13 of those agreed to take part in a research interview 4-5 months later
- In both sets of interviews, the eye witnesses were asked to give their account and then follow up questions were asked.
- The researchers asked 2 misleading questions
- Half the group were asked if they saw A broken headlight and the other half were asked if they saw THE broken headlight. There was no broken headlight.
- Half of the group were asked if they saw A yellow panel on the car and the other half were asked if they saw THE yellow panel. The panel was in fact blue.
- The witnesses were then asked to rate their degree of stress of a scale of 1-7. They were also asked if they had any emotional problems since the event.
reports of other professionals attending the scene
each detail was awarded 1 point
Results of Yuile and Cutshal Study
Results -
number of details recalled
police interview = 649.5
research interview = 1056.5
Conclusion of Yuile & Cutshal Study
misleading Qs had no effect
amount of incorrect info recalled was considerably lower than lab research reported
Aim of Valentine T & Mesout J
To investigate if high stress can decrease a witnesses ability to identify a perpetrator
and recall information about the event
Participants of Valentine T & Mesout J
56 participants
27 m, 29 f
opportunity sample
Procedure of Valentine T & Mesout J
base heart rate was measured before and during tour
participants given tour around London Dungeon
at one point a man in a scary mask and costume jumped out
after tour
given questionnaire — measure state anxiety
given 20 likert scale — measure trait anxiety
reported on the facial features/ gave description of perpetrator
asked to identify perpetrator from a 9 person line up
(all had similar feature, makeup and dress)
asked to rate the confidence of their identification
Results of Valentine T & Mesout J
-strong - correlation between state correlation between state anxiety and accuracy of description
-only 17% of those above the mean state anxiety score correctly identified the perpetrator
-75% of those below the mean state anxiety score correctly identified the perpetrator
Conclusion of Valentine T & Mesout J
higher levels of anxiety impair eyewitness memory and ability to correctly identify a perpetrator
Evaluation of Valentine T & Mesout J
G - low as an opportunity sample was used
so participants are more likely to be those that deal with stress better (willing but themselves in this stressful situation)
high as there was a large sample size and an equal m and f split
R - high as study is easily repeatable due to standardised questionnaire and 20 likert scale
A - high as it can be used to inform the reliability of EWT due to stress and how they can be highly unreliable
V - high ecological validity as it was a field study not a lab study
low ecological validity as it was in london dungeon rather than witnessing a real crime + participants aware they’re not in an actually dangerous situation
high as questionnaire was first validated by being tested on office workers
E - high as they gained informed consent before study and participants could withdraw
Aim of Loftus & Messo
To provide support for ‘weapon focus’ effect when witnessing a crime
To investigate if ‘weapon focus’ effect influences ability to correctly identify a perpetrator
Participants of Loftus & Messo
-36 University students
-age 18-31
-volunteer sample
-psych and non-psych students
Procedure of Loftus & Messo
Procedure -
split into 2 groups
all shown 18 slides of a series of events in a taco restaurant
same for each group apart from one slide (IV)
control group — slides shows person handing the cashier a cheque
experimental group — slide shows person pulling a gun on the cashier
each slide shown for 1.5s
DV - recognition of this person in later questioning
shown a line up of 12 h&s shots
asked how confident they were in m,asking correct identification
eye fixation time on cheque/gun also measured
given questionnaire on events
Results of Loftus & Messo
-higher % of correct identifications for control condition than for experimental condition
-no dif in confidence level
-significant dif in eye fixation time
-no dif in recall of other aspects of the events
Conclusion of Loftus & Messo
weapon focus does occur and the presence of a weapon does affect ability to recognise and identify a perpetrator
may not affect knowledge of other aspects of the crime
Aim of Pickel
To test whether unusualness is the key variable in the weapon focus effect rather than degree of danger
Participants of Pickel
230 undergraduate psychology student
Procedure of Pickel
split into 5 groups
-all watched a 2min video of a scene from a hair salon
-a man walks to the receptionist and she hands –him money
-the man holds something dif in each video
nothing (control)
-scissors (high threat, low unusualness)
-handgun (high threat, high unusualness)
-wallet (low threat, low unusualness)
-raw chicken (low threat, high unusualnes –asked to fill out a questionnaire, asked about:
-receptionist (control)
- the man
-description of him
-what he was doing
identify him from a line up
Results of Pickel
no dif in accuracy of descriptions of man in low threat conditions to high threat conditions
EW accuracy was significantly worse for high unusualness conditions
Conclusions of Pickel
-the unusualness of a weapon in certain conditions is what affects recall in the ‘weapon focus’ effect NOT the threat/danger of a weapon
Aim of Bradbury & Williams
To investigate if the racial makeup of a jury affects its decision making
Procedure of Bradbury & Williams
-collected data from trials held in 2000 and 2004
-data included
-type of charge
-jury decision
-demographic characteristics of defendant and victim
-jury selection
-trial evidence
-jury deliberations
-selected trials with only black defendants
-IV: conviction or no conviction
-DV: racial makeup of jury
% white, black or hispanic
Strength of prosecutors case was measure by:
-quality of evidence
-witness presented
case type considered:
violent, petty or drug crime
Results of Bradbury & Williams
Results -
-higher the % of white jurors, the higher the likelihood of conviction of black defendants
-higher the % hispanic jurors, the higher the likelihood of conviction of black defendants
jurors less likely to convict black jurors of violent crime compared to drug crimes
Conclusion of Bradbury & Williams
-racial makeup of jury compared to race of defendant does impact jury decision making
Evaluation of Bradbury & Williams
G — low as only cases with black defendants were used and data was on,y from 4 US states in 2000 and 2004
A — high for Jury selection process and devising ways to make it fairer for all
V — high due to many control variables to ensure only racial makeup of jury was being investigated
content analysis so quantitative data was used (high objectivity)
E — high as it was just a review of cases so no direct involvement
Aim of Penrod & Cutler
To investigate whether the presence of an expert witness would affect the juror’s decision-making ability
Procedure of Penrod & Cutler
-used videotaped mock trial of a robbery
-4 IVs
-witness identifying conditions (good/poor)
-witness confidence (good/poor)
-expert opinions expressed (high/low)
-for of expert testimony (descriptive/statistical)
-then given questionnaire
-guilty or not guilty
-confidence in verdict
-memory of trial and expert psychologist testimony
Results of Penrod & Cutler
Results -
-juror gave more guilty verdicts when witness identification conditions were good
increased if psychologist used simply descriptive language
juror confidence was higher in good witness identification conditions and high witness confidence
Conclusion of Penrod & Cutler
Conclusion
-expert testimony improved jurors knowledge of factors that may affect accuracy of EWT and made them pay more attention to witness identification conditions
