Memory - Factors Affecting Eyewitness Testimony

Memory - Factors Affecting Eyewitness Testimony

1. Misleading Information

   • Leading Questions
     • A question that leads the witness to a certain answer or suggests an answer that is desirable is a leading question
     • Loftus and Palmer (1974)
       • Procedue
         • Lab experiment, independent groups
         • 45 US students showed seven films of car accidents with a questionnare
         • One critical question: 'How fast were the cars going when they ________ each other?"
         • Space replace by words ranging in intensity from "contacted" to "smashed"
       • Findings
         • The groups with the less intense words estimated lower than the groups with the more intense words
       • Conclusion
         • Language can have an effect on answers given in an EWT
   • Post-Event Discussion
     • Any information discussed after an event can affect a persons memory of it
     • Gabbert et al (2007)
       • Procedure
         • 210 young and old adult volunteers took part in a lab experiment where they viewed a simulated crime event
         • Paired with a confederate who either introduced misinformation in discussion of it was presented in a written narrative
         • Participants filled out a questionnaire with 4 critical questions
       • Findings
         • Participants were less accurate when they spoke to the confederate
       • Conclusion
         • Witnesses can often go along with each other (NSI or ISI)

2. Anxiety

   • The emotional state of anxiety that a lot of witnesses are in during the event lead to differences in how information is coded and stored. Research suggests recall is best when anxiety is at a medium level
   • The Weapon Focus Effect - Loftus et al
     • Procedure
       • Two experimental conditions, participants were asked to sit outside a room where the different conditions occurred
         • Low (no weapon) - peaceful conversation about office equipment, a man emerged holding a pen
         • High (weapon) - heated conversation, breaking glass, a man emerged holding a knife covered in blood
     • Findings
       • Low condition- 49% correctly identified man,
       • High condition - 33% of people correctly identified man, the weapon may have distracted them
     • Loftus and Burns completed a controlled study where participants watched a film of a simulated robbery, one violent and one not, non-violent condition recall was better

3. Evaluation

   • High reliability as lots of experiments have gained similar results and controlled lab experiments means no confounding variables
   • Situation could be too artificial, a video isn't as unexpected and dramatic as in real life so they lack ecological validity
   • Other research that studied real life situations suggests that EWT in real life are not as easily distorted
   • Ethical issues - unnecessary psychological harm can't be put onto participants so measuring EWT's in an ecologically valid way is difficult