eye witnesses testimony (EWT)☑️

factors affecting the accuracy of EWT

misleading information

-police may influence using leading questions and wording to give a particular answer; affects EWT

loftus and palmer (1974) 45 p’s watched car crash film clips + were questioned on what they had seen. wording was manipulated; some p’s were asked how fast the cars were going when they "smashed" into each other, others having the word "hit." the subtle wording change significantly affected the speed estimates, demonstrating how easily memory is influenced by external factors.

findings

the mean estimate speed for ‘contacted’ was 31.8mph, and 40.5mph for 'smashed', illustrating the impact of language on memory recall of events

why leading questions affect EWT

-response-bias explanation: wording has no real effect on memories; just influences recollections. implies witnesses adjust their memories to align with the expectations set by question phrasing, leading to testimony inaccuracies. (‘smashed’ encourages them to choose a higher speed estimate while neutral 'hit' likely results in a more conservative estimate), demonstrating how subtle variations in language can shape event recollection.

research on post-event discussion

gabbet et al (2003) paired p’s each watched a video of the same crime from different angles; one saw elements of the event the other could not, they discussed what they had seen before individually completing a recall test.

71% of p’s recalled aspects of the events they did not see in the video but had picked up in the discussion. control group with no discussion was 0%, showing evidence of memory conformity (NSI), and memory contamination

why does post-event discussion affects EWT?

-memory contamination: when co-witnesses to a crime discusses their recollection of events, their EWT becomes altered or distorted from combining (mis)information from other witnesses to their own memory.

-memory conformity: where witnesses alter their memories to match others due to ISI or NSI, further complicating EWT. unlike memory contamination, the actual memory is unchanged.

evaluation of factors affecting accuracy of EWT (misleading information)

strengths

-practicality for the criminal justice system - loftus (1975) showing leading questions affect memory aided development of the cognitive interview, improving the legal system and decreasing faulty convictions; high external validity

counterpoint: loftus and palmers p’s watched film clips in a lab - different from witnessing a real event (less stressful). foster et al. (1994) p’s are less motivated to be accurate, suggesting researchers are too pessimistic ∴ EWT may be more dependable than suggested.

evaluation of factors affecting accuracy of EWT (misleading information)

limitations

∴

-sutherland and hayne (2001) showed p’s video and questioned with misleading questions. more accurate recall for central details than peripheral ones - presumably because attention was more focused on them so memories were more resistant to misleading info: not predicted by the substitution explanation.

-evidence that post-event discussion alters EWT: skagerberg and wright (2008) showed partnered p’s variant film clips (difference was hair colour). recall was often a blend, not just one p’s answer, suggesting memory contamination is more prominent than memory conformity.

factors affecting EWT accuracy (anxiety)

negative affect on recall (weapon focus)

-anxiety affects psychological arousal, preventing attention to important cues, so recall is worse

johnson and scott (1976) p’s in a waiting room (low-anxiety condition) heard a casual conversation in the next room, then saw a man walk past carrying a pen with grease on his hands.

high-anxiety condition heard a heated argument, accompanied by breaking glass. a man walked out the room holding a blood covered knife

findings

p’s picked the man from a set of 50 photos: 49% in the low-anxiety condition were able to identify him, and 33% were able to identify the man holding the blood-covered knife.

tunnel theory of memory: people have enhanced memory for central events; weapon focus as a result of anxiety.

anxiety having a positive effect on recall

-the fight or flight response, physiological arousal the body, may improve memory for the event by improving cue awareness.

yullie and cutshall (1986) 13/21 witnesses from actual bodega shooting recall events five months post-incident. accuracy determined by the number of details reported in each account, asked to rank their fear on a scale and whether they had had emotional problems since.

findings and conclusions

-little changed in the amount recalled (very accurate accounts); p’s who reported highest stress levels were most accurate, suggesting anxiety doesn’t have a detrimental effect on accuracy of eyewitness memory in a real world context, and could even enhance it.

explanation for mixed research on anxietys affect of EWT

yerkes-dodson (1908) relationship between emotional arousal and performance is an inverted U. performance will increase with stress, only to a certain optimal point, where it decreases drastically if the optimum point is exceeded.

evaluation of factors affecting EWT accuracy (anxiety)

strengths

-countering evidence. valentine and mesout (2009) researchers used heart rate (objective measure) to divide p’s into high and low anxiety groups; significant difference suggests anxiety has a negative effect on the immediate EWT of a stressful event.

-evidence suggesting positive effects: christianson and hubinette (1993) interviewed 58 robbery witnesses; workers and bystanders. the direct witnesses (workers) had more accurate recall than bystanders. suggests, from findings from actual crimes, anxiety doesn’t reduce accuracy of recall for EWT

evaluation of factors affecting EWT accuracy (anxiety)

limitations

johnson and scott may not have tested anxiety; reason for p’s focusing on weapon could have been due to surprise rather than fear. pickel (1998) experiment using scissors, handgun, wallet or a raw chicken as the handheld item in a hairdressing salon video. EWT was significantly poorer in high unusualness conditions, suggesting weapon focus effect is due to unusualness rather than anxiety/ threat and tells us nothing about the effects of anxiety on EWT

improving the accuracy of EWT - cognitive interview

fisher and geiselman (1992) EWT could be improved if police used better interviewing techniques based on psychological insights

1. report everything

2. reinstate the context

3. reverse the order

4. change perspective

1- report everything

-encourage witness to include every detail of the event even if it seems irrelevant and the witness doesn’t feel confident about the accuracy as seemingly trivial details may be important or trigger other memories

2- reinstate the context

-witness should mentally return to original crime scene, imagining the environment (weather, senses, emotions at the time) for context-dependant forgetting

3- reverse the order

-events should be recalled in a different order from original sequence to prevent people reporting their expectations of how event happened rather than reporting the actual events + prevents dishonest accounts (harder to produce an untruthful account reversed)

4- change perspective

-witnesses should recall the incident from the perspective of others (eg of other witnesses, victim or perpetrators) to disrupt expectations and the effect of schema on recall (contrast between what would have happened vs what actually happened)

enhanced congnituve interview (ECI)

fisher et al. (1987) developed additional elements of the CI to focus on the social dynamic of the interaction (eg interviewer know when to establish eye contact and when to relinquish it)

-ECI also includes reducing witness anxiety, minimising distractions, getting the witness to speak slowly and asking open-ended questions

evaluation of improving accuracy of EWT - cognitive interview

strengths

-evidence that it works: kohnken et al. (1999) meta-analysis of 55 CI and ECI comparison studies with a standard police interview. the CI gave 41% increase in accurate information, showing CI is effective to recall information that is available but not immediately accessible

counterpoint: kohnken et al found increase in amount of inaccurate information recalled by p’s (more with ECI). sacrifices EWT quality for quantity, so should treat EWT with caution.

evaluation of improving accuracy of EWT - cognitive interview

limitations

-not all elements are equally effective or useful. milne and bull (2002) each technique used alone produced more information, but using a combination of first two steps produces better recall than any other combination, suggests some steps are more important than others, casting doubt in overall credibility of CI

-police reluctant to use CI; time consuming and requires more training. many forces don’t have the resources for this (kebbell and wagstaff 1997) - not a realistic method.