cognitive

• The reliability EWT is a widely debated issue as there have been cases of wrongful convictions which questions if they are reliable enough to use in the justice system
• the three themes of EWT:

  • post event information
  • presence of a weapon
  • emotive crimes
• EWT are not reliable due to post-event info:

  • Loftus & Palmer - "smashed" condition gave higher speed estimates
  • Loftus and Zanni - 7% saw 'a' broken headlight where as 17% saw 'the' broken headlight
• EWT are reliable despite post event info:

  • studies likes Loftus and Palmer have low external validity as they are lab based and not 'real' events
  • Loftus - 98% of ppts remebered the purse had been red after misleading info that the purse was brown
• the presence of a weapon can make EWT unreliable:

  • Johnson and Scott - invited ppts to a lab and either heard a discussion ('no weapon' condition) or a heated exchange and a bloody letter opener ('weapon' condition)
  • no weapon = correctly identified 49% of the time out of 50 photos compared to 33%
  • weapon focus effect = higher levels of anxiety and more likely to focus on the weapon
• presense of a weapon doesnt lead to unrelaible EWT:

  • Yuille and Cutshall - EW of a real life armed robbery had accurate recollection 4 months later despite 2 misleading questions
  • an armed robber stole guns and money from a shop. the thief fired 2 shots at owner and the owner shot 6 back killing the thief
• emotive crimes will affect accuracy of memory:

  • Freud - painful/threatening memories are repressed (ego defence mechanism) into the unconscious mind so they are forgotten
  • Briere and Conte - 267 adults who had been abused as children, 59% could identify times when they had no recollection of the abuse
• emotive crimes make EWT more reliable:

  • flashbulb memory - accurate long lasting memory from emotionally shocking events
  • Cahill and Mcgough - ppts more likely to recall details of a distressing story (boys feet severed) then a mundane one (hospital visit)
• ethical implications:

  • Huff - 60% of 500 cases of wrongful convictions involved EWT errors
  • ethical implications to victim and wrongful accused
• social implications:

  • real criminal is able to walk free and commit further crimes
  • however, the Police and Criminal evidence act offers a code of practice when carrying out identification attempts eg. no leading questions
• economic implications:

  • cost of re-trails and compensation for the wrongfully convicted
  • max amount of compensation in UK is 1 million
  • adds to the overall costs of crime = 124 billion
• conclusion:

  • difficult to prove if they are reliable or not
  • research has led us to be more critical of EWT and the factors that might reduce its reliability
  • important practical applications such as the cognitive interview
  • increased use of CCTV mean EWT will be less likely to be unreliable