Eyewitness Testimony

• Refers to an account given by people of an event they have witnessed.

  • EWT is an important area of research in cognitive psychology and human memory: Juries tend to pay close attention to eyewitness testimony and generally find it a reliable source of information.
• Factors affecting EWT: 


  1. Leading questions - Loftus and Palmer's (1974)
  2. Post-event discussion - Gabbert et al. (2003)
• Loftus and Palmer's LQ (1974) sample: 45 American students divided into 5 groups of 9. P's watched a video of a car crash and asked a specific question about the speed of them.

  • Loftus and Palmer manipulated the verb used in the question, for example: 'How fast were they cards going when they contacted / smashed / collided / bumped /hit / with each other?’
  • ​​Estimated speed was affected by the verb used. The results clearly show that the accuracy of eyewitness testimony is affected by leading questions and that a single word in a question can significantly affect the accuracy of our judgements.
• Loftus and Palmer's LQ (1974) possible explanations:

  1. Response-bias factors: The misleading information provided may have simply influenced the answer a person gave but didn't actually lead to a false memory of the event. eg. different speed estimates occur because the critical word influences or biases a person's response. 2. The memory representation is actually altered: The critical verb changes a person's perception of the accident - some critical words would lead someone to have a perception of the accident being more serious - this perception is then stored in a person's memory of event.
• A second experiment by Loftus and Palmer supported that memory may actually be altered: 150 students watched a 1minute video of a car accident and were then asked of the speed. One week later the participants were asked the critical question: “Did you see any broken glass?”

  32% of ‘smashed’ group reported seeing broken glass 

  14% of ‘hit’ group reported seeing broken glass

  12% of control group reported seeing broken glass 

  There was no broken glass in the video and participants questioned using ‘smashed', were significantly more likely to report seeing glass.
• • Gabbert et al. PED (2003) studied p's in pairs. Each p watched a video of the same crime, but filmed from different perspectives - so each participant could see different elements in the event that others couldnt.
  • Gabbert et al. then paired participants then discussed what they had seen before individually completing a recall test.
  • Gabbert et al. (2003) found that 71% of participants mistakenly recalled aspects of the event that they did not see in the video but picked up in the discussion. In the control group where there was no discussion – this was 0%.
• Supports:


  • Important practical uses 

  Improving the way the legal system works and by appearing in court as expert witnesses.
• Limitations


  • Artificial tasks

  May tell us very little about real crime. It could even be that researchers are too pessimistic about the accuracy of EWT and it may be more reliable than many studies suggest.

  • Individual differences 

   Anastasi & Rhodes (2006) - reduces validity

  • Demand characteristics 

  Zaragosa & McCloskey (1989) - reduces validity

  • Consequences of EWT

  Foster et al. (1994)