Eyewitness Testimony

Eyewitness Testimony

1. One type of memory that has particular relevance in everyday life is EWT. It's a legal term referring to the use of eyewitnesses to give evidence in court concerning identity of someone who has commited a crime. Juries & police officers seem to place great importance on EWT but there is evidence to suggest that this faith in accuracy of EWT is misplaced. In 75% where people have been found by DNA evidence to have been wrongly convicted, the original guilty verdict was based on inaccurate EWT.

   • 3 factors influencing accuracy of EWT:
     • Misleading info, Anxiety, Age of witness

2. 1) The effect of misleading info on accuracy of EWT:

   • Research shows that EWT is affected by experiences occuring after the witnessed event. Misleading info can occur in 2 ways:
     • 1) Leading questions- questions that are worded in such a way that it might bias how responder answers.
       • 2) Post-event info- misleading info added to question after incident occurs.
         • In a similar experiment they also found that info given after the event influenced ppts EWT. Ppts were divided into 3 groups & shown a film of a car accident. Group 1 asked- "How fast were the cars going when they smashed each other?" Group 2- "How fast were cars going when they hit each other?" Group 3- did not have any questions about speed. When ppts asked week later. "Did you see any broken glass?" ppts in smashed condition mistakenly reported broken glass compared to those in conditions 2 & 3.
         • Loftus conducted another experiment looking at post-event info. She showed ppts a film of events leading up to a car accident. After seeing the film, they were divided into control group & an experimental group. Control group asked questions consistent with what they'd actually seen. whereas experimental group asked a question that included misleading information. She found that 17% of ppts in experimental group reported seeing a barn in original film but only 3% of control group made this error. Loftus concluded that some of the ppts given the misleading post-event info had actually absorbed this with their original memory for the event & now really believed they had seen a barn.
       • An example of this is the study by Loftus & Palmer who asked ppts to estimate speed of cars in film containing traffic accidents. Ppts divided into 5 conditions & asked specific questions about crash. They were asked "About how fast were the cars going when they **** each other" The **** was altered for each question, it was either hit/bumped/smashed/collided/contacted. Loftus & Palmer found that the estimate of the car speed varied depending on the word used in the question. Ppts gave higher speed estimates of 41mph when the word "smashed" was used compared to 34 mph when the word "hit" was used.

3. Evaluation of the effect of misleading info on accuracy of EWT

   • Loftus' work has been criticised for the artificiality of her lab experiments. It is difficult to reproduce in the lab the kind of events, which arise spontaneously in real life so the studies lack ecological validity. Being robbed in real life or witnessing an accident will create psychological arousal & this may effect our memory of the event.
   • The results of her studies show that witnesses can be very inaccurate but this could be because they know the inaccuracies won't lead to any serious consequences. Foster showed ppts video of bank robbers & asked them to identify robbers in an identity parade. 1 group was lead to believe the robbery was a real event & that their influences would effect the trial, while the second group assumed it was a simulation. Identification of the robber was more accurate for the fisrt group, suggesting consequentiality is an important factor for witnesses.