Eyewitness testimony - notes without evaluation

Bartlett (1932) stated that memories are not accurate 'snapshots' of events but are actually reconstructions influenced by schemas; these are mental representations about what we know and understand about a person, situation or object and are based on our expectations, previous experiences, attitudes stereotypes and moods. Schemas help us to make sense of the world by filling in the gaps in our knowledge. This means that eyewitnesses are not just recalling a factual account of what they saw but could be reconstructing memories that are biased by schemas, and this can lead to false memories. Psychologists have identified a number of factors that can affect the reliability of eyewitness recall.

Misleading information (leading questions and post-event discussion)

Leading questions

Loftus and Palmer aimed to investigate the effects of leading questions on the reconstruction of memories. The method involved using 45 university students who were shown 7 short video clips of car crashes. All of the participants were asked to write an account of what they saw as well as being asked specific questions, the key one being to estimate the speed of the vehicles. They were split into 5 conditions, with 9 participants in each one. Each group was given a different verb to fill in the blank for the question - 'about how fast were the cars going  when they ...... each other?' These verbs were smashed, collided, bumped, hit or contacted. Participants estimate of speed was recorded.

How the question was phrased influenced the participants' speed estimates. When the verb 'smashed' was used, participants estimated that the cars were travelling much faster than when the verb 'contacted' was used.

Loftus and Palmer concluded that memory is open to being reconstructed as a result of the way questions are asked. Language can therefore have a negative effect on the accuracy of eyewitness testimony. A week later participants were asked if they had seen any broken glass. Loftus and Palmer found that participants who had been asked the 'smashed' version of the question were more likely to report having seen broken glass at the scene of the accident, even though there was none.

Post-event discussion

Wright carried out a study to investigate the effect of post-event discussion between witnesses on recall of an event. Two groups of participants were shown a series of story pictures about a woman stealing a man's wallet. In one condition, the woman was alone at the start of the story; in the other condition she had an accomplice. After viewing the pictures, participants answered questions about the story, including a question about whether the woman had an accomplice. At this stage both groups showed accurate recall. Participants were then put into pairs, with one person from each…