eye witness testimony

• eye witness testimony is the ability of people to remember the details of events such as accidents and crimes, which they themselves have observed
• misleading information is incorrect information given to the eye witness after the event which can affect their testimony
• leading questions are questions that suggest a certain answer e.g was the knife in the accused left hand
• post event discussio (PED): is when the witness discusses the event which influences their memory of the event.
• loftus and palmer conducted an investigation where 45 participants where split into 5 groups. each group was shown a clip of a car crash and after where asked about the speed of the car. however each group was given a different verb e.g smashed, hit, bumped
• loftus and palmer found that depending on the verb their speed prediction changed. for smashed/crashed the average prediction was (42mph) but for hit/ bump the average was (33mph) this supports the misleading questions theory
• part two of the l and p experiment was asking the participants wether they saw broken glass. they found that participants that were given the verb smashes gave more yes answers then participants given hit which further supports misleading question theory
• disadvantages of the loftus and palmer investigations are that it cannot be generalised due to small sample, it also lacks ecological validity as lacks real life representatio. advantages are that resukts are reliable and can be replicated
• Gabbert et al investigated post event discussion by putting participants into pairs then having each participant watch a video of the same crime but from different point of views. They then discussed what they had seen before completing a recall test. It was found that 71% of participants mistakenly recalled they did not see in the video compared to 0% in a control group with no discussion. This supports memory contamination and conformity
• Memory contamination is when memories from witnesses get mixed up with other people’s memories
• memory conformity is when memories merge with other peoples memories as a way to fit in.
• anxiety is a state of emotional and physical arousal for example feeling tension this can lead to an increased heat rate which can effect the accuracy and detail of the eye witness testimony
• the weapon focus effect is a state of witness regarding people that focus on the weapon to the extent that they cannot remeber the details
• johnson and scott investigated the impact of weapon focus effect by having participants sit in a waiting room then have someone walk in holding a pen with greasy hands for condition 1 then have someone walk in holding a bloody knife for condition 2 a week later it was found that 48% of condion 1 had accurate ewt compared to 39% in condition 2 which supports weapon focus effect
• yuille and cutshall investigated effect of anxiety of recall of participants by interviewing 13 witnesses four to five months after and comparing that to their original interviews. they also asked how stressed they felt on at the time of the incident. it was found that the recall was very accurate and the participants who were the most stressed had 88% accurate recall compared to the lese stressed group at 75% which therefore shows anxiety does not have an effect on recall
• The cognitive interview (CI) is a questioning technique used by the police to enhance the retrieval of information about a crime scene from the eyewitness’s and victim’s memory.
• there are four parts of the cognitive interview which include report everything, recall from a changed perspective, context reinstatement and recall in reverse order
• report everything is when witnesses are encouraged to include every single detail of the event even if it feels irrelevant or the witness is not confident about it as it may be important and trigger other memories
• recall from a changed perspective involves asking the witness to imagine themselves looking at the event from different perspectives such as above or below this can help them remember more details
• context reinstatement is when witnesses should return to the scene of the crime in their mind and imagine the environment and their emotions at the time to help them remember
• recall in reverse order is where the witness is asked to describe the events backwards this allows them to think back over the whole sequence of events rather than just focusing on one part and stops them from reporting their expectations and being dishonest
• fisher et al conducted research on cognitive interview using real witnesses and 16 different detectives from florida police. 7 of the detectives were trained in cognitive interview. he found that 63% more information was obtained by the detectives trained in cogntive interview which suggests that its much more accurate and effective.
• yerkes and dodson investiagted optimum anxiety levels by having participants be put into 4 conditions 2 with low and 2 with high unusualness and 2 with high and 2 with low anxiety. they found that recall was better in the lower anxiety but high unusualness condtion.