outline and evaluate research into the effects of misleading information on eyewitness testimony Flashcards
outline loftus and palmer (1975)
first experiment (lab experiment, independent groups, volunteer sampling) 45 ppts shown a film of a car crash and questioned. critical question asked “how fast were the cars going when they hit each other”
5 groups of ppts and each given a different verb: hit, bumped, contacted, collided or smashed
- different verbs suggested speed, meaning ppts were asked a leading question
- smashed - fastest estimated speed, contacted least
suggests leading question biased eyewitnesses recall of event; verb smashed indicated greater speed than verb contacted
experiment 2: 150 ppts shown 1 minute film of car driving through countryside then 4s of multiple traffic accident
- students questioned about the film; 3 groups of 50
1st group - “how fast were the cars going when they hit”, 2nd “when they smashed”, 3rd control who were not asked a question
1 week later, without seeing the film again, asked a leading question “did you see broken glass” but there was none
- those who heard the more violent verb were more likely to claim there was broken glass so, wording of leading question changed memory of the clip; change in critical verb altered their memory of the clip
2 explanations as to why leading questions affect EWT: response-bias explanation states wording of questions has no effect on memories but it can influence how they answer (exp 1)
substitution explanation suggests wording of a question does affect memory of eyewitness; interferes with original memory, distorting its accuracy (exp 2)
Strength of L & P
Strength of research into misleading information is that it has important real life applications
As it has led to practical uses for police and investigators when interviewing witnesses
Loftus (1975) claimed that leading questions can distort memory and therefore police officers need to be aware of how they phrase questions when interviewing eyewitnesses
Research into EWT makes a real difference to our lives, for example, by improving how the legal system works
Limit of L & P
Limitation of L&P study is that it used artificial materials, lowering the ecological validity meaning the findings cannot be generalised to other settings
This is because participants watched film clips of car accidents, which is a very different experience from witnessing a car accident in real life
Film clips lack the emotion associated with witnessing a traumatic event; Yuille and Cutshall (1986) found that witnesses to a traumatic robbery had very accurate recall after 4 months
This means that the results of this study may tell us little about how leading questions can affect EWT in cases of real life crimes or accidents
outline 2
gabbert 2003 looked into effect of post event discussion (lab, independent, volunteer) 60 aberdeen uni, 60 older adults shown video of young girl stealing from wallet
- in pairs, believed same video but from diff perspectives
- free to discuss what they had seen before individually completing a test of recall
71% ppts who watched recalled info they had not seen
- 60% said she was guilty despite not seeing her commit a crime
control group w no discussion > no recall errors
- shows when witnesses discuss their memories of an event, contaminate memories of others making them think they have witnessed something they have not
gabbert concluded witnesses go along with each other either to win social approval or bc they believe other witnesses are right and they are wrong (memory conformity) f
Strength of Gabbert
Gabbert et al’s study is that it has high control over extraneous variables
Which are variables that could have an undesirable effect on the results if they are not properly controlled, affecting internal validity of the results
As the experiments were lab experiments, extraneous variables, such as the length. Of time participants watched the video for can be controlled
This means we can be certain the misleading information led to the difference in judgements and not other factors
Limitation of research into EWT
Many studies lack external validity
Meaning the findings of research cannot be generalised to other settings, wider populations and over time
Foster et al (1994) have argued that the information you remember as an eyewitness can have very important consequences in the real world; the testimony an eyewitness gives in real life could lead to a successful or wrongful conviction if the information is inaccurate, so they may make more effort to recall information
The same is not true in research studies; this means that the accuracy of EWT may be greater in the real world because of the seriousness with which eyewitnesses undertake their role
