Accuracy of eyewitness testimony: Misleading information

Leading questions. Experiment 1) 45 students, 7 films diff traffic accidents. Given questionnaire, asked to describe accident then answer questions. 1 critical question - how fast going when hit each other? - word hit replaced in each condition - contacted, bumped, collided, smashed etc. Leading question as suggests answer - speed of car. Smashed - 40.8mph, contacted - 31.8mph.

Experiment 2) leading q may bias participant's response or may cause info to be altered before stored. New set of participants, 3 groups, shown film for car accident 1 min long, asked q's about speed. Asked to return 1 week later when asked series of 10 q's about accident inc 'did you see any broken glass?' - critical q. No broken glass in film, but if thought travelling faster, might think would be broken glass (diff verbs used eg smashed, hit) Leading q changeed memory of event.

Co-witnesses may reach consensus view of what happened. Investigated by Gabbert et al (2003). Participants in pairs where each partner watched diff video of same event so each viewed unique items.

Pairs in 1 condition encouraged to discuss event before each partner individually recalled event they watched. High number of witnesses (71%) who'd discussed event went on to mistakenly recall items acquired during discussion.

Each time eyewitness interviewed there is possibility that comments from interviewer will become incorporated into recollection of events. Interviewer may use leading questions + therefore alter individual's memory for events. Especially the case when children being interviewed about crime - LaRooy et al (2005).

Supporting evidence for misleading info - Loftus - cut-out bugs bunny. College students asked to evaluate advertising material about Disneyland. Embedded in material, misleading info about either Bugs Bunny or Ariel (neither been seen at Disneyland b/c Bugs Bunny not Disney + Ariel not intro'd at time of childhood). 3 conditions; Bugs, Ariel, control (no misleading info). All visited Disneyland. In Bugs/Ariel groups more likely to report having shaken hands w/ characters than control group. Shows how misleading info can create inaccurate memory.

Individual diffs - age diffs could be consequence of source monitoring. Eyewitness typically acquires info from 2 sources - observing event + subsequent suggestions (misleading info). Number of studies eg Schacter et al (1991) found compared to younger, elderly hae difficulty remembering source of info, even though memory for info unimpaired. Result - more prone to effect of misleading info when giving testimony.

EWT in real life - Loftus' research suggests EWT generally inaccurate therefore unreliable. Not representative of real life. Yuille + Cutshall (1986) found evidence of greater accuracy in real life. Witnesses to armed robbert in Canada - accurate reports of crime 4 months after event even though initially given miselading q's. Suggests misleading info may have less influence on real life EWT.

Real world applications - CJS relies on EWI for investigating + prosecuting crimes. Psych research been used to warn justice system of problems w/ EWI evidence. Recent DNA exoneration cases confirmed warnings of EWI resarchers by showing mistaken EWI largest single factor contributing to conviction of people - Wells + Olsen (2003).