Eyewitness testimony (EWT)

Eyewitness testimony (EWT)

1. Definition

   • Encoding
     • Retains
       • Retrieves

2. Accuracy

   • Loftus and Palmer
     • Leading questions
     • Changed the verb
       • Hit to smashed
     • Speed estimate was higher with smashed
   • Yuille and Cutshall
     • Armed robbery
       • Real life event
     • 4 months later with leading questions- no effect

3. Misleading information

   • Loftus and Palmer
     • Asked if they saw broken glass
     • Smashed verb- more 'saw' glass
   • Loftus et al
     • 41% given a misleading question picked correctly
     • 'STOP' and 'YIELD'
   • Bekerian and Bowers
     • Replicated the Loftus study
     • Gave the slides in original order
       • Now no difference in recall
         • Misleading questions affect retrieval not storage

4. Anxiety

   • Deffenbacher et al
     • Meta-analysis of 18 studies
     • High levels of stress negatively impacted accuracy
   • Christianson and Hubinette
     • 58 witnesses to bank robberies
     • Anxiety increased accuracy of EWT
   • Contradiction of the studies explained by the Yerkes-Dodson law
   • Weapon-focus effect
     • Loftus et al
     • 49% accurate if man has pen
     • 33% accurate with knife

5. Age

   • Parker and Carranza
     • Identification after mock crime
     • Kids chose more but were wrong
   • Yarmey
     • Young and middle aged more confident
     • No difference in accuracy
   • Memon et al
     • No difference if short delay
     • Older were less accurate with a week delay
   • Anastasi and Rhodes
     • Own age bias
       • Differential experience hyp
         • More contact = better memory for them