Factors effecting EWT

• Factors affecting EWT

  • Misleading info
  • Leading Questions
  • Post-event discussion
  • Anxiety
• Misleading info - Barlett

  • Barlett argued that memories are not accurate snapshots of events.
  • memories are instead reconstructions of events, influenced by attitude and stereotypes.
  • Therefore he developed schemas.
  • We use schemas to construct our memory
  • Reconstructive memory is not an accurate recording of events, as when recunstructed in recall, it may produce confabulations.
• Schemas in relation to memory

  • Packages of information about people in the world.
  • We use schemas as mental shortcuts
  • When we recall a memory, it is influenced by schemas and memories can change to fit with the individuals bias.
• Leading questions


  Questions that imply a particular answer can influence how a memory is recalled.

  Either due to the Substitution bias explanation or the response bias explanation.
• The Substitution bias explanation is an actual change in memory
• The response bias explanation is where emotional pressure makes an individual give a particular response.
• Post-event discussion

  • This is When the recalling of events by one witness alters the accuracy of recall from another witness.
  • This can be memory conformity where the witness goes along with others for social approval
• Research support of leading questions - Loftus and Palmer

  • PPTs were shown clips of traffic accidents.
  • After watching the clip they were asked leading questions.
  • "how fast were the cars going when they ___ into each other"
  • The verb was changed to (Smashed, collided, bumped, hit, or contacted.)
  • Found that the more extreme the verb the faster the estimation of MPH.
  • Contacted = 31.8, smashed 40.8.
  • Suggesting misleading info in the form of leading questions can influence EWT.
• Research support of post-event discussion - Gabbert et al

  • Videos of crimes shot from different perspectives were shown to pairs of participants.
  • There was different unique info in each video.
  • Found that 71% of pairs that discussed what they had seen included aspects they could not have seen in the recollection of the video.
  • Compared to 0% with no discussion
  • Suggests that witnesses will change their account of crimes to match other witnesses as they seek social approval.
• Anxiety

  • a mental state of arousal that includes feelings of extreme concern and tension
  • High levels of anxiety can decrease recall of the criminal's face.
  • Weapon focus is an explanation as weapons are a cause of anxiety, witnesses are distracted and focus on the weapon rather than the criminal.
  • Anxiety can also increase recall as it improves alertness and awareness of the situation and surroundings, strong emotions can also improve memory encoding.
• Yerks-Dodsons Law of arousal

  • EWT accuracy increases as anxiety rises because the witness becomes alert.
  • However, at a point, anxiety becomes too high and more stress/distraction results in lower accuracy.
• Research support of anxiety - Johnson and Scott.

  • PPTs were placed outside a lab, listening to conversations.

  1. Normal convo about equipment failure, a man walks out with greasy hands and a pen.
  2. hostile, breaking glass, furniture knocked over, a man walks out with a knife covered in blood.

  • PPTs were then asked to identify the man.
  • It was found that more PPts identified a man with a pen than a knife.
  • Suggesting anxiety is caused by the knife due to weapon focus.
• Peters

  • PPTs at a real healthcare centre were given a real injection by a nurse, with a researcher present in the room.
  • Found that the patients were better able to recognise the researcher than a nurse.
  • Suggests Anxiety was caused by having an injection, (weapon focus on the syringe)
• Yuille and Cutshall

  • Interviewed 13 witnesses to a deadly shooting, 4 months after the event.
  • Found that witnesses resisted misleading info and those with the most stress produced the most accurate EWT.
  • Suggesting misleading info and anxiety may not be a significant problem in EWT.
• Additional Eval

  • + Research has led to real-life applications. (Cognitive interview)
  • + Study's like Loftus were done in a lab rather than a court, meaning people were less worried about consequences of incorrect EWT.
  • Demand characteristics in researching leading questions.
  • Ethical issues.