7. Accuracy of eyewitness testimony: Misleading information

state 4 factors affecting accuracy of EWT

misleading information

(leading questions)

(post-event discussion)

anxiety

Loftus and Palmer (1974)

A: investigate effect of leading questions on accuracy of EWT

P: 45 students shown seven short films of a car crash. after each film, each pp was given a questionnaire with the critical question being “how fast were the cars going when they hit/smashed/collided/bumped/contacted each other?“

F: the mean speed estimates given were highest when the more intense verbs were used (e.g. smashed = 40.8 mph, but contacted = 31.8 mph)

C: suggests memory is unreliable as leading questions can alter memory in EWT

Gabbert et al (2003)

A: investigate effect of post-event discussion on memory

P: pps were put into pairs. each pp watched a video of the same crime, but filmed from different POVs. witness A did not witness the crime, but witness B did = both witnesses saw different details of the event. both pps then discussed what they had seen before individually completing a test on recall

F: 71% of pps reported inaccurate information they they had picked up in the discussion, compared to 0% in the control group (no discussion)

C: memory conformity effect = witnesses go along with each other to gain social approval or because of ISI

LaRooy et al (2005)

each time an eyewitness is interviewed, there is a possibility that comments from the interviewer will become incorporated into their collection of events

this is especially the case when children are being interviewed about a crime

one strength of research into the effect of misleading information on memory is there are real world applications

Loftus (1975) believes that leading questions can distort memory to such a large extent = police officers need to be very careful how they phrase their questions when interviewing eyewitnesses

improves accuracy of EWT = decreases number of false imprisonments = saves money on compensations = economic benefits

one limitation of research into the effects of misleading information is the tasks are artificial

Gabbert (2003) has pps watching video recordings, and the pps are not real witnesses = less anxiety

Yuille and Cutshall (1986) found that witnesses to an armed robbery in Canada gave very accurate reports of the crime four months after the event despite being asked two misleading questions

lacks mundane realism, reduces ecological validity

questionable appropriateness/value of research in making conclusions about the effect of misleading information on memory

one limitation of research into the effect of misleading information on memory is the use of a biased sample

Loftus and Palmer (1974) used a biased sample of 45 American students

culture bias = beta bias

students have limited driving experience = may inaccurately estimate driving speeds

findings are non-generalisable

question the appropriateness and value of this research into investigating effects of leading questions on memory