Loftus & Palmer, Johnson & Scott - A01

• Factors affecting EWT:

  • Leading questions
  • Post-event discussion
  • Anxiety
• Procedure of Loftus & Palmer (1974): To investigate effect of leading questions on accuracy of EWT.

  Carried out a laboratory experiment using independent group design. 45 American students shown 7 films of different car accidents. Given questionnaire asking specific questioning including one critical question - how fast cars were going when they (verb) each other. Participants divided into 5 groups each with different verb:

  1. Hit
  2. Smashed
  3. Collided
  4. Bumped
  5. Contacted
• Findings of Loftus & Palmer (1974): Found that estimated speed was affected by verb used. Group given 'smashed' estimated highest speed of 40.8mph while group given 'contacted' estimated lowest speed of 31.8mph.
• Conclusions of Loftus & Palmer (1974): Questions asked can be termed as leading as they have affected participants answers. Language can have distorting effect on eye witness testimony - can lead to inaccurate accounts of witness.
• Procedure of Gabbert et al (2003): To investigate effect of post-event discussion on accuracy of EWT.

  Participants split into pairs, watched same crime video but from different viewpoints - could see different elements that the other could not see. Both participants then discuss what they had seen before individually completing recall test. In control group no discussion before recall test.
• Findings of Gabbert et al (2003): In experimental condition 71% participants mistakenly recalled aspects they did not see in video but had picked up from discussion. In control condition 0%.
• Conclusions of Gabbert et al (2003): Post-event discussion can alter eye witness testimony, accuracy can be manipulated as additional memories can be added.
• Procedure of Johnson & Scott (1976): To investigate whether high levels of anxiety affect accuracy of recall in EWT.

  Used 2 experiment conditions, participants asked to sit outside lab where they heard discussion between two people. Low anxiety (no weapon) condition, conversation was peaceful and man emerged holding pen with grease on his hands. High anxiety (weapon) condition, conversation heated participants heard broken glass and man emerged holding knife covered in blood. All participants asked to identify man from 50 photographs.
• Findings of Johnson & Scott (1976): Found that in low anxiety condition 49% participants able to accurately identify man. In high anxiety condition memory recall less with 33% participants able to accurately identify man. Known as 'weapon focus effect' - witnesses central focus on details of attack (e.g. weapon) and miss peripheral details (e.g. what perpetrator looked like).
• Conclusions of Johnson & Scott (1976): Suggests anxiety (physiological arousal) prevents individuals from paying attention and plays role in EWT affecting what is seen and recalled. Higher levels of anxiety could reduce ability to remember correctly.
• Procedure of Loftus & Burns (1982): To investigate whether high levels of anxiety affect accuracy of recall in EWT.

  Participants watched film of stimulated robbery; some watched non-violent version (low anxiety condition), some watched violent version where boy shot in face(high anxiety condition).
• Findings of Loftus & Burns (1982): When questioned afterwards, those who watched non-violent version recalled significantly more details of the crime than those who watched violent version.
• Conclusions of Loftus & Burns (1982): The higher the anxiety the more the accuracy of recall affected.
• Contradictory Findings - The Inverted U Theory:

  Findings into EWT effect are contradictory explained by Yerkes-Dodson law.

  Lower anxiety = lower levels of recall

  Increase in anxiety = accuracy of recall increases

  Optimal level of anxiety reached = point of maximum accuracy

  More anxiety above optimal = drastic decline in recall