Factors affecting accuracy of EWT (Misleading Info + Anxiety) & Improving accuracy of EWT (Cognitive Interview) Flashcards
Describe the stages of cognitive interview
Fisher and Gieselman designed cognitive interview:
1) CONTEXT REINSTATEMENT: - return back to original crime scene “in their mind” and imagine the environment and their emotions - so external cues that were available at learning will also be available at recall to prevent context dependent forgetting
2) REPORT EVERYTHING: - encouraged to include every single detail, although it may seem irrelevant or they may not feel confident about it - trivial details may be important or may trigger more important memories
3) RECALL FROM CHANGED PERSPECTIVE: - recall the incident from other people’s perspective - to prevent the effect of schema and expectations on recall
4) RECALL IN REVERSE ORDER: - events should be recalled in a different order to the original sequence - prevents witnesses reporting their expectations of what should have happened rather than the actual event - prevents dishonesty as it is harder to give untruthful account in reverse order
Evaluate cognitive interview
1) Meta- analysis by Kohnken et al combined from 50 studies shows ECI consistently provided more correct information than SI
- strength - bc real practical benefits of the police using ECI, as it has provided a greater chance of catching criminals so more beneficial for society
2) Mello and Fisher compared older and younger adults memory of a filmed stimulated crime
- CI produced more information than SI but this was greater for older ppts than younger ppts
- Giselman reviewed a number of studies and found children under age of 6 recalled events less accurately in CI
3)Limitation - police may feel reluctant to use CI because it takes more time than SI. So, police may not perform ‘proper’ version of the CI. It also requires more special training, so budget cuts and lack of resources may make it impractical to use CI. This could be overcome if the CI was reduced so that it was more time and cost effective
What factors affect eyewitness testimonies?
Anxiety and misleading information may affect eyewitness testimonies.
Describe research on the effect of leading questions on eyewitness testimony.
- Loftus and Palmer made participants watch film clips of car accidents and then gave them questions about the accident. There were five groups of participants, each was given a different verb (e.g hit, contacted, bumped, collided, smashed)
- Findings: Loftus and Palmer found the verb ‘contacted’ resulted in a mean estimated speed of 31.8 mph. Whereas, the verb ‘smashed’ resulted in a mean estimated speed of 40.5 mph. This shows the leading question biased eyewitness recall on the event.
Why do leading questions affect eyewitness testimony?
- The response bias explanation suggests that the wording of the question has no real effect on the participants’ memories but just influences how they decide to answer. When participants get a leading question using the word ‘smash’ it encourages them to choose a high-speed estimate.
Loftus and Palmer conducted a second experiment that supported the substitution explanation - they found wording of a leading question actually changed the participants’ memory of the film clip. Participants who heard the verb ‘smashed’ were more likely to report some broken glass (although there was none) than those who had heard ‘hit’.
The critical verb altered their memory of the incident.
Describe how post event discussion may affect the accuracy of eyewitness testimony?
- Gabbert studied participants in pairs, the participants watched a video of the same crime, but from different points of view. This meant that each participant could see elements in the event that the other could not. Both participants discussed what they had seen before individually completing a test of recall.
- Findings: Gabbert found that 71% of the participants mistakenly recalled aspects of the event that they did not see in the video but had picked up on in the discussion. Comparatively, the figure in the control group, where there was no discussion, was 0%. Gabbert et al concluded that witnesses often go along with each other either to win social approval or because they believe the other witnesses are right and they are wrong - they called this memory conformity.
Evaluate research into misleading information
Loftus and Pickrell presented participants with stories from when they were between 4 and 6 years old, 3 of which were true, and 1 false (getting lost in a shopping mall). Ppts were asked to write down all the details of the events they recalled straight after reading them, in an interview a week later. After the week, they were then told one of the memories was fake and 5/24 ppts falsely recalled the ‘lost in the mall’ event as a real memory.
- This shows misleading information does have an effect on the accuracy of EWT, as it shows when ppts are told information they believe it is true even thought it is false.
- The implications of false memories is that they can give false eyewitness testimonies which could lead to false imprisonment.
Bodner et al found that the effects of post event discussion can be reduced if ppts are warned of the effects. Equally police officers now know the dangers of using leading questions in investigations.
- This shows research into misleading information has real world applications. Since we know the effects, we stop post discussion occurring before testimonies. This has benefits as it prevents people being falsely imprisoned because of false testimonies.
Yuille and Cutshall found evidence of greater accuracy in real life. Witnesses to an armed robbery in Canada have very accurate reports of the crime 4 months after the event, despite being given 2 leading questions.
- This refuted the lab research on misleading informations. This indicates the effects Loftus and Palmer found may only be applicable to lab experiments. So, research has low external validity.
There are more severe consequences in real life research as there are more risks if something goes wrong. Whereas, in lab experiments, emotions are absent so results lack external validity due to mundane realism. In lab experiments, ppts may perform demand characteristics or perform the please you, screw you effect, that reduces the internal validity of results
Describe the effect of anxiety on the accuracy of eye witness testimonies
Anxiety has a negative effect on recall because it creates physiological arousal in the body which prevents is from paying attention to important cues, so recall is worse.
Johnson and Scott (Weapon Focus Effect):
- Participants believed they were taking part in a lab study.
- In the low anxiety condition, ppts heard a heated argument in the next room while they were seated in the waiting room. A man walked through the waiting room with a pen and with grease on his hands.
- In the high anxiety condition, ppts overheard the same heated argument, but this time accompanied with breaking glass. A man out of the room, holding a paper knife that was covered in blood.
- The ppts later had to pick out the men from 50 photos. 49% of ppts in low anxiety condition were able to point him out but only 33% in high anxiety condition could point him out. The tunnel theory of memory argues that a witness’s attention narrows to focus on a weapon, because it is a source of anxiety.
Anxiety has a positive effect on recall because it creates physiological arousal within the body. The fight or flight response is triggered which increases our alertness and improves our memory for the event because we become more aware of cues in the situation.
Yuille and Cutshall:
They studied a real life shooting in Canada, where a shop owner shot a thief. 13 witnesses agreed to be in the study. Interviews were held 4-5 months after the incident and these were compared with the original police interviews after the shooting. The accuracy was determined by the number of details reported in each account. Witnesses were asked how stressed they were at the time using a 7 point scale and asked if they had any emotional problems since the event e. g sleeplessness
They found very accurate recall, there was little change in accuracy of recall after 5 months. Ppts who reported highest levels of stress were most accurate (about 88% compared to 74% of less stressed group).
Explain the contradictory anxiety findings
According to Yerkes and Dodson’s inverted U theory, performance will increase with stress but only up to a certain point where it decreases drastically.
Deffenbacher applied the Yerkes and Dodson’s law to EWT.
- Lower levels of anxiety produce lower levels of accuracy.
- Memory becomes more accurate as the level of anxiety experienced increases, just as expected from the graph.
- However, there comes a point where the optimal level of anxiety is reached. This is the point of maximum accuracy.
- If an eyewitness experiences any more stress that this, than their recall of the event suffers a drastic decline.
Evaluate the effect of anxiety on eyewitness testimonies
Pickle consisted an experiment using either scissors, a hand gun, a wallet or raw chicken as the hand held items in a video of a hairdressing salon. The scissors represented the low anxiety and unusualness condition and the other items either unusual or anxiety making or both. Eyewitness accuracy was significantly poorer in the high unusualness conditions (handgun and chicken).
- This opposes the weapon focus effect theory because it suggests the unusualness of the object causes the weapon theory effect rather than anxiety.
The advantages of Yuillle and Cutshall’s research is that it has high ecological validity, whereas Johnson and Scott’s research had demand characteristics which could’ve invalidated results. It also can’t create same levels of anxiety in controlled settings
-However, Deffenbacher et al found from a review of 34 studies, that real life studies result in a greater loss of accuracy compared to lab studies. Deffenbacher suggests Yuille and Cutshall’s research is less accurate because of the traumatic feelings involved. Since there is not a clear link, accurate conclusions can’t be drawn.
Fazed and Hardy suggested catastrophe theory which predicts that when physiological arousal increases beyond optimum level, there is a dramatic decline (not a gradual one as the inverted U hypothesis. This is because of increased mental anxiety whereas the inverted U only describes physiological anxiety.
Key issue is that research into effect of anxiety on EWT could breach ethical guidelines such as protection of participants. Investigators must protect participants from physical and mental harm during the investigation. Investigation like this also sometimes require deceptive consent or no consent for them to work
