Factors affecting eye-witness testimony

• factors affecting eye witness testimony

  
  

  • leading questions
  • post event discussion
• leading questions 


  questions that are worded to suggest a particular answer
• loftus and palmer (1974)


  leading question varied between conditions with one group asked how fast the vehicles were going when they “hit” each other while other groups had verbs implying different degree’s of a collision such as “bumped, smashed, contacted, collided”.

  resulting in different speeds for the same video
• post event discussion


  the way an event is remembered can also be altered or contaminated by discussing events with others and/or being questioned repeatedly.
• loftus and pickrell (1995) investigated how misleading information could create false memories in individuals. 


  Participants were then asked questions on whether they recalled these stories and results found 29% of the fake stories were recalled by participants believing them to be true. 68% of the true stories were recalled correctly also. 
• conformity effect

  when co-witnesses reach a consensus view of what they think happened from discussing. (Gabbert et al (2003))
•  How does anxiety affect eyewitness testimony?

  Anxiety can affect eyewitness testimony by impairing memory recall and causing witnesses to focus on irrelevant details. High levels of anxiety can also lead to overconfidence in the accuracy of memory recall.
• What is the Yerkes-Dodson law? (Deffenbacher)


  states that performance on a task improves with increased arousal or stress up to a point, after which it starts to decline.

  This means that moderate levels of anxiety may actually enhance memory recall, but high levels can have a detrimental effect.
• loftus et al: weapon focus effect

  The group who observed the pen were more accurate (49%) than the group observing the violent situation (33%).
• What is weapon focus?

  where witnesses focus their attention on a weapon during a crime, often to the detriment of their memory recall of other details.
• How can we improve the reliability of eyewitness testimony?


  using open-ended questions rather than leading questions, avoiding suggestive language, and using video or audio recordings of the witness’s initial statement.
• Christianson (1993) et al


  When witnesses to real bank robberies were tested on recall, they found increased anxiety led to improvements in the accuracy of recall.

  
  

  suggests high levels of anxiety in situations do not always divert attention away from what is happening.
• Strengths of Post Event Discussion

  • The laboratory condition allowed researchers to control for extraneous confounding variables and clearly see the link between leading questions and recall.
  • The laboratory setting has also made it easier to verify results for reliability through replication and establish cause and effect relationships between leading questions and memory recall which would be difficult to do in real-world settings. 
• Weaknesses of Post event Discussion


  • Laboratory studies lack ecological validity and realism. Due to this, results gained in such settings may lack external validity and wider generalisation.
  • The use of questionnaires is a weakness as questions can be easily misunderstood by participants or misinterpreted without clarification. 
• Evaluation of EWT & the anxiety of the witness: Strengths

  • Yuille & Cutshall used real-life EWs which means that their research is high in ecological validity
  • Loftus et al. replicated their experiment with another 80 students and achieved the same results which means that the findings have good reliability
• Evaluation of EWT & the anxiety of the witness- Weaknesses

  • Yuille & Cutshall used a small sample of participants who had witnessed a one-off event. Difficult to generalise the findings
  • In Loftus' study numerous ethical guidelines were broken. The participants were deceived about the nature of the experiment and not protected from harm. 
  • Loftus’s research lacks ecological validity. Although the participants were waiting in the reception area outside the laboratory, they may have anticipated that something was going to happen. This could have affected the accuracy of their judgements.