Eyewitness testimony

• What are leading questions?

  • When the wording of a question leads or misleads you to give a certain answer
  • Particular issue for eyewitness testimony as police questions may direct a witness to give a particular answer that may not reflect the truth
• What research is there on leading questions?

  • Loftus and Palmer (1974): had 45 student participants watch film clips of car accidents and then asked them questions about it - the critical leading question asked them to describe how fast the car was going
  • 5 groups were each given a different verb like 'smashed', 'collided', 'bumped', 'contacted'
  • Verb 'contacted' received a mean speed of 31.8 mph but the verb 'smashed' received 40.5 mph, showing that the leading question biased the eyewitness' recall of the event
• Which 2 explanations explain why leading questions affect eyewitness testimony?

  • Response-bias explanation: the wording of a question doesn't affect the ppts. memory but how they decide to answer e.g. when they get a leading question with the word 'smashed' they are encouraged to estimate a higher speed
  • Substitution explanation: the wording of a leading question changes the ppts. memory of the film clip
  • Loftus and Palmer (1974) - second experiment showed that ppts. who heard the world 'smashed' were more likely to report seeing broken glass than those who heard 'hit', showing the critical verb altered their memory of the incident
• What is post-event discussion?

  • When eyewitnesses of a crime discuss their experiences and memories with each other
  • This may influence the accuracy of each witness' recall of the event
• What research is there on post-event discussion?

  • Gabbet et al. (2003) had pairs of participants watch a video of the same crime filmed from different points of view, so each ppt. could see elements that others could not - both then discussed their experiences and then independently completed a recall test
  • 71% of ppts. mistakenly recalled elements that they didn't see in the video but picked up in the discussion, compared to 0% of a control group
• Which 2 explanations explain why post-event discussions affects eyewitness testimony?

  • Memory contamination: during PED, eyewitness testimonies become distorted or altered because witnesses combine misinformation from other witnesses with their own memories
  • Memory conformity: witnesses often go along with each other to either win social approval or because they believe other witnesses are right and they are wrong - but the actual memory remains unchanged (supported by Gabbet et al 2003)
• What is one strength of research into misleading information?

  • Real-world application: due to serious consequences of inaccurate EWTs from the distorting effect of leading questions on memory, Loftus (1975) urged police officers to be careful about how they phrase their questions
  • Psychologists can be asked to act as witnesses in court + to explain limits of EWT to juries
  • Shows understanding can help improve the way the legal system works, protecting innocent people from faulty convictions based on unreliable EWT
• What is one limitation of research into misleading information?

  • Evidence against substitution: Sutherland and Hayne (2001) showed ppts. a video clip and later asked them misleading questions
  • Recall was more accurate for central details rather in peripheral ones, showing that ppts. attention was focused on central features of the event which were relatively resistant to misleading info
  • Suggests original memories for central details were not distorted, which the substitution explanation did not predict
• What is another limitation of research into misleading information?

  • Evidence against memory conformity: Skagerberg and Wright (2008) showed ppts. 2 versions of a film clip where a mugger's hair was either dark brown or light brown which they then discussed in pairs
  • Found that ppts. did not report what they saw or what co-witnesses saw but a 'blend' of both e.g. giving the answer 'medium brown' when asked about his hair colour
  • Suggests memory is distorted through contamination by misleading PED rather than the result of memory conformity
• What is another limitation of research into misleading information?

  • Issues with research: Loftus and Palmer's study was lab-based which doesn't reflect the stressful experience of witnessing a real event
  • Foster et al. (1994) pointed out that eyewitness recall has serious consequences in the real world but none in research, meaning they have less incentive to be accurate
  • Suggests researchers are pessimistic about the effects of misleading info and EWT may be more dependable than studies suggest
• How does anxiety have a negative effect on recall?

  • Anxiety creates physiological arousal in the body preventing us from paying attention to important cues, worsening recall
  • Weapon focus effect: in crimes where a weapon is used an eyewitness may fixate attention on the weapon due to fear or fight-or-flight
  • Due to this intense focus, details about the perpetrator such as height or hair colour are not really noticed
• What research is there into the weapon focus effect?

  • Johnson and Scott (1976): had participants who believed they were taking part in a lab study hear 2 different scenarios while seated in a waiting room
  • Low-anxiety condition: overheard a casual conversation in another room and a man walk past with a greasy pen in his hand
  • High-anxiety condition: overheard a heated argument with the sound of breaking glass and a man walk out of the room with a knife covered in blood
  • Ppts. picked out the man from a set of 50 photos - 49% could identify the greasy pen man but only 33% could identify the bloody knife man
  • Supports negative effects of anxiety on recall through WFE
• How does anxiety have a positive effect on recall?

  • Anxiety creates physiological arousal in the body triggering the fight-or-flight response, increasing our alertness
  • This may improve memory as we become more aware of the cues in the situation
• What research is there into the positive effects of anxiety on recall?

  • Yuille and Cutshall (1986) interviewed 13 witnesses of an actual shooting in a Canadian gun shop 4 to 5 months after the incident, compared to original police interviews at the time of the shooting
  • Witnesses were asked to rate their stress on a scale and accuracy was determined by how detailed their recall was
  • Witnesses were very accurate, saw little change in recall - those ppts. who reported HIGHEST stress levels were the MOST accurate
  • Suggests anxiety isn't detrimental to EWT in real-world context and may even enhance it
• How can we explain the contradictory findings of research into the effects of anxiety on EWT?

  • Yerkes-Dodson law: lower levels of anxiety/arousal produce lower levels of recall accuracy, and then memory becomes more accurate as the level of anxiety/arousal increases
  • However there is an optimal level of anxiety which is the point of maximum accuracy - any more arousal means recall will suffer a drastic decline
• What is one strength of research into the effects of anxiety on EWT?

  • Research support for negative effects: Valentine and Mesout (2009) had visitors of a Horror Labyrinth use wireless heart monitors to measure anxiety and complete a questionnaire describing an actor they encountered
  • Only 17% of high anxiety ppts. could correctly identify the actor compared to 75% of low anxiety ppts. who could correctly identify them
  • Suggests high anxiety levels have a negative effect on immediate eyewitness recall of a stressful event
• What is another strength of research into the effects of anxiety on EWT?

  • Research support for positive effects: Christianson and Hubinette (1993) interviewed 58 witnesses to a real Swedish bank robbery, some of which were directly (bank workers) and indirectly involved (bystanders)
  • Recall was over 75% accurate across all witnesses - direct victims who were most anxious were even more accurate
  • Findings from real crimes confirm anxiety may even enhance accuracy of recall for eyewitnesses
• What is one limitation of research into the effects of anxiety on EWT?

  • Christianson and Hubinette interviewed their ppts. several months after the event - had NO control over whether ppts. engaged in post-event discussion in the intervening time
  • Effects of anxiety may have been overwhelmed by confounding variables which explain the results, invalidating their support for the positive effects of anxiety on EWT
• What is another limitation of research into the effects of anxiety on EWT?

  • Unusualness not anxiety: Pickel (1998)' experiment had ppts. watch a hairdressing salon video where hand-held items were scissors, a handgun, a wallet, or a raw chicken with conditions of high/low anxiety, high/low unusualness
  • Eyewitness accuracy was poorest in the high unusual conditions e.g. the chicken and handgun, suggesting WFE is due to unusualness rather than anxiety and decreasing the internal validity of research into the negative effects of anxiety on recall