factors affecting the accuracy of eyewitness testimony - misleading information

Question 1

loftus and palmer study

Answer 1

procedure - 45 participants watched film clips of car accidents and then asked questions, the critical question was ‘about how fast were the cars going when they hit each other?’, each of five groups was given a different verb in the question - hit, contacted, bumped, collided, smashed

findings - mean estimated speed was calculated for each group. contacted - 31.8 mph. smashed - 40.5 mph. the verb used in the leading question biased the eyewitness’ recall of an event

type - lab
IV - verb used in critical question
DV - average speed reported in mph for each verb
experimental design - independent groups

Question 2

why do leading questions affect the EWT?

Answer 2

• the response bias explanation suggests that the wording of the question has no real affect on the participants’ memories but instead how they decide to answer the question
• when using the word ‘smashed’ participants decide to use a higher speed estimate

Question 3

loftus and palmer second experiment on substitution explanation

Answer 3

• loftus and palmer did a second experiment, supported the substitution explanation that proposed that the wording of the leading question changes the participants’ memories of the clip
• participants who heard the word ‘smashed’ were later more likely to report seeing broken glass in the clip (there was none) than those who heard ‘hit’
• the critical verb altered participants’ memory of the clip
• makes sense that there would be broken glass in a car accident so fits in with schemas, more violent language used in question
• activated car crash schema so led to inaccurate reporting

Question 4

loftus and palmer evaluation

Answer 4

• low ecological validity, would be more anxiety if witnessing a real life car crash
• low mundane realism, would probably pay more attention to the video compared to a real crash
• high reliability, can be replicated as the same video and questions can be used
• low external validity, leading questions won’t influence everyone in the same way due to individual differences

Question 5

overall findings

Answer 5

smashed - 40.5 mph
contacted - 31.8 mph

smashed - 16 said yes, 34 said no
hit - 7 said yes, 43 said no
control (no speed question) - 6 said yes, 44 said no

Question 6

what is post-event discussion?

Answer 6

when eyewitnesses may discuss their experiences and memories with each other

Question 7

gabbert et al study

Answer 7

procedure - studied participants in pairs, each participant watched a clip of the same crime but from different POVs, so each person saw things that others couldn’t see, for example title of a book etc. both participants then discussed what they saw before completing a recall test.

what they observed - a girl stealing a wallet, half saw the girl stealing, half didn’t.

findings - 71% of participants mistakenly recalled aspects that they didn’t see but that they had discussed, 60% of people said that the girl had stole the wallet even though they hadn’t seen this. this first figure in a control group, where there was no discussion, was 0%. evidence of memory conformity.

IV - perspective through which the crime was viewed and whether they discussed afterwards (control group)
DV - results of recall test
experimental design - matched pairs
type - lab experiment

Question 8

gabbert evaluation

Answer 8

• high reliability, standardised and can be replicated because the same video and recall test can be used
• multiple studies have been done to support the negative impact of post event discussion

Question 9

why does post-event discussion affect EWT?

Answer 9

memory contamination - when co-witnesses to a crime discuss with each other, their EWTs may become altered or distorted, they combine info from other witnesses with their own memories.

memory conformity - witnesses often go along with each other, either to win social approval or because they believe that the other witnesses are right and that they are wrong. unlike with memory contamination, the actual memory is unchanged.

Question 10

conformity theory

Answer 10

• we want to be seen to agree with others because we tend to assume that others are right and we are wrong
• if they say something we didn’t, we assume that its because we missed it

Question 11

source monitoring theory

Answer 11

• repeated exposure to things through sight, sound or just imagination can muddle memories or even mean that they recall an experience that isn’t real

Question 12

practical applications - in the police

Answer 12

• police attempt to keep eyewitnesses separate
• only interview one person at a time
• don’t ask people if they saw specific details
• avoid including any new post event info