Why it might work
Stages of the Interview
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A leading question is a question, usually asked during the course of a police investigation, which unwittingly has an effect on the recall of information. Note: the examiners may ask a question using the phrase ‘misleading information’ rather than leading question.
Much of the research in the area has been carried out by Elizabeth Loftus. (A woman and as such is to be referred to by the following personal pronoun: ‘she’ as opposed to ‘he’ which is reserved for those of us with one X and one Y chromosome!). Proof of Liz’s genetic make up is provided in the photo on the left! Evidence too that generally female psychologists are more attractive than their male counterparts |
Loftus & Palmer (1974)
The researchers showed participants a series of slides of car crashes. They were then asked ‘How fast the cars going when they bumped into each other?’ The verb (the doing bit) was substituted for other participants with words such as ‘smashed’ or ‘hit.’ An average speed for each verb was then calculated.
Findings: the estimated speed varied according to the verb used. ‘Smashed’ produced an average estimate of 41mph whereas ‘hit’ reduced the estimates to 34mph and to 32mph for ‘contacted.’ A week later participants were asked if there was broken glass from a headlight. This time participants who had received the verb ‘smashed’ were more likely to recall seeing glass.
Conclusion
Loftus had shown how language and wording could influence a person’s recall of an incident.
Evaluation
Loftus had concentrated on minor details of the incident. Research suggests that our recall of key details is not so prone to leading questions. The study lacks ecological validity. The use of clips does not recreate the emotion of a real life incident. The study employed students who are hardly representative of the population as a whole.
Loftus & Zanni (1975)
The effects of wording can also be more subtle. In a similar study participants were asked questions using either the definite article (‘the’) or indefinite article (‘a’ or ‘an’). So for example: ‘Did you see the broken headlight?’ or ‘Did you see a broken headlight?’ Participants asked ‘the’ were twice as likely to recall seeing the broken headlight as those asked ‘a’.
Christianson & Hubinette (1993) found that fear does have an effect. They asked people involved in real bank robberies, either as victims or as onlookers, about the incident. The recall of the victims was more accurate than that of the onlookers, suggesting the stress of the situation had aided recall. The better recall was still present 15 months later.
Evaluation of Loftus’ Research
Lack of ecological validity (as already stated). The participants are shown slides so are not exposed to any trauma, adrenaline rush or emotional involvement that would be present at a genuine incident. Research has suggested that emotions can impact significantly on memory, either having a positive or negative effect on recall.
Other researchers have found that when participants are led to believe the incident they’ve witnessed is real then their recall is more accurate.
Similarly recall may be less accurate because participants know their response will not have serious consequences for others. Participants were shown video footage of a bank robbery and later asked to spot the robbers in an identity parade. Those led to believe the footage was genuine were more likely to recognise the right person.
Loftus tends to use a forced choice format in which participants have to choose between one option or another (similar to multiple choice). Some research suggests that recall is more accurate if participants have an open choice, or more importantly have the option to give no answer at all.
Finally, Loftus was only able to alter recall for minor details. The participants recall of the bigger picture and of main events remained unchanged by misleading information.
Other factors that may affect accuracy of EWT
Anxiety
Clearly our levels of anxiety may have an impact on our ability to recall events.
Deffenbacher et al (2004) carried out two meta analyses comparing the effects of anxiety on a. facial recognition and b. details at the scene of the crime. In both cases high levels of anxiety were shown to significantly reduce accuracy of recall.
However, some research suggests that anxiety can have beneficial effects. Christianson and Hubinette (1993) questioned 110 witnesses to 22 real bank robberies and found that those who had been threatened during the raids had a more accurate recall of events.
These seemingly contradictory findings could be explained by the Yerkes-Dodson Law. Simply stated this suggests that moderate levels of anxiety can be beneficial to recall, however, as anxiety continues to increase it begins to have an adverse effect. There does appear, however, to be an optimal level of anxiety.
The inverted U relationship or Yerkes-Dodson law
The researchers showed participants a series of slides of car crashes. They were then asked ‘How fast the cars going when they bumped into each other?’ The verb (the doing bit) was substituted for other participants with words such as ‘smashed’ or ‘hit.’ An average speed for each verb was then calculated.
Findings: the estimated speed varied according to the verb used. ‘Smashed’ produced an average estimate of 41mph whereas ‘hit’ reduced the estimates to 34mph and to 32mph for ‘contacted.’ A week later participants were asked if there was broken glass from a headlight. This time participants who had received the verb ‘smashed’ were more likely to recall seeing glass.
Conclusion
Loftus had shown how language and wording could influence a person’s recall of an incident.
Evaluation
Loftus had concentrated on minor details of the incident. Research suggests that our recall of key details is not so prone to leading questions. The study lacks ecological validity. The use of clips does not recreate the emotion of a real life incident. The study employed students who are hardly representative of the population as a whole.
Loftus & Zanni (1975)
The effects of wording can also be more subtle. In a similar study participants were asked questions using either the definite article (‘the’) or indefinite article (‘a’ or ‘an’). So for example: ‘Did you see the broken headlight?’ or ‘Did you see a broken headlight?’ Participants asked ‘the’ were twice as likely to recall seeing the broken headlight as those asked ‘a’.
Christianson & Hubinette (1993) found that fear does have an effect. They asked people involved in real bank robberies, either as victims or as onlookers, about the incident. The recall of the victims was more accurate than that of the onlookers, suggesting the stress of the situation had aided recall. The better recall was still present 15 months later.
Evaluation of Loftus’ Research
Lack of ecological validity (as already stated). The participants are shown slides so are not exposed to any trauma, adrenaline rush or emotional involvement that would be present at a genuine incident. Research has suggested that emotions can impact significantly on memory, either having a positive or negative effect on recall.
Other researchers have found that when participants are led to believe the incident they’ve witnessed is real then their recall is more accurate.
Similarly recall may be less accurate because participants know their response will not have serious consequences for others. Participants were shown video footage of a bank robbery and later asked to spot the robbers in an identity parade. Those led to believe the footage was genuine were more likely to recognise the right person.
Loftus tends to use a forced choice format in which participants have to choose between one option or another (similar to multiple choice). Some research suggests that recall is more accurate if participants have an open choice, or more importantly have the option to give no answer at all.
Finally, Loftus was only able to alter recall for minor details. The participants recall of the bigger picture and of main events remained unchanged by misleading information.
Other factors that may affect accuracy of EWT
Anxiety
Clearly our levels of anxiety may have an impact on our ability to recall events.
Deffenbacher et al (2004) carried out two meta analyses comparing the effects of anxiety on a. facial recognition and b. details at the scene of the crime. In both cases high levels of anxiety were shown to significantly reduce accuracy of recall.
However, some research suggests that anxiety can have beneficial effects. Christianson and Hubinette (1993) questioned 110 witnesses to 22 real bank robberies and found that those who had been threatened during the raids had a more accurate recall of events.
These seemingly contradictory findings could be explained by the Yerkes-Dodson Law. Simply stated this suggests that moderate levels of anxiety can be beneficial to recall, however, as anxiety continues to increase it begins to have an adverse effect. There does appear, however, to be an optimal level of anxiety.
The inverted U relationship or Yerkes-Dodson law
This relationship states that stress or anxiety increases performance up to an optimal point. After that, further increases in anxiety lead to a falling off of performance. This also seems to apply to the relationship between anxiety and recall.
In the studies mentioned above it seems reasonable to assume that research showing improving performance were describing patterns to the left of the graph and those showing impairment were describing patterns to the right
In the studies mentioned above it seems reasonable to assume that research showing improving performance were describing patterns to the left of the graph and those showing impairment were describing patterns to the right
Individual differences
Bothwell et al (1987) tested various participants for their level of neuroticism (how much of a worrier). They then witnessed a ‘crime’ and had to identify the culprit from an ID parade. When exposed to low levels of stress the participants high in N (worriers) tended to out-perform the ones low in N. However, when exposed to high levels of stress, the outcome was completely reversed with the participants scoring high on neuroticism now performing significantly worse.
High stress + High neuroticism = Low recall
Weapons focus
In some ways related to anxiety, it isn’t really surprising that faced with a knife or gun toting maniac you’re most likely be focusing you’re attention on the weapon rather than the attacker. Loftus et al 1987 got participants to listen to a squabble between two people, one sounding more violent than the other. In the quieter affair a man with greasy hands emerges holding a pen. Following the noisy, violent sounding incident a man emerges with a blood drenched knife. Participants could accurately recall the identity of the ‘pen-fiend’ on 49% of occasions but the knifeman on only 33%. In a follow up Loftus recorded eye movements and found the focus of attention was the knife, diverting attention from the identity of the perpetrator.
However, most research into weapons focus has been lab based. In real life situations there seems to be less impact than research would predict. Studies have found that the presence of a weapon has little impact on accurate identification of culprits in real-life identity parades!
EWT and Age
The relationship between age and recall of events is also more complex than may be expected. You can probably guess that the older we get the more fragile our cognitive (and other functions) so generally wrinklies tend to make less reliable eye witnesses. However, evidence also suggests that the young are prone to errors too.
Young people and EWT
Poole and Lindsay (2001) got children of varying ages (three to eight) to watch a science demonstration following which they listened to a story which contained some of the science material but also some new information. Later when they were questioned about the science demonstration it was found that they threw in some of the story as well. In a follow up they were asked to consider where they had got the information from (the demonstration or the story). The older children could mostly do this successfully but the ones in the younger age group were less able to distinguish the source of the information. Poole and Lindsay therefore concluded that since young children are poor at ‘source recognition’ they are unlikely to make for good eye witnesses.
Pozzulo and Lindsay (1998) carried out a meta analysis of identification parade studies, particularly comparing the results of different age groups. The three main findings were as follows:
1. Children below the age of five were least likely to make correct identifications when the culprit was present in the line-up
2. Children over five were just as likely as adults to identify the culprit when they were present.
3. Children up to the age of thirteen were more likely than adults to make an identification when the culprit was NOT present in the line-up.
Conclusion
It seems that younger children are far more prone to suggestion than adults. Possible reasons for this may include:
1. They may yield to social pressure, especially when questioned by someone much older than themselves
2. They continue to believe in their distorted recall because of deficits in their cognitive abilities. They continued to make false statements even after they had been told they were making mistakes.
The cognitive interview (CI)
This was based largely on the work of Elizabeth Loftus and other psychologists, following their theoretical work into memory and EWT. Forensic psychologists combined various ideas and designed a more effective way of questioning witnesses that has been shown to produce more reliable recall of events. Fisher and Geiselman (1992) designed the cognitive interview.
The technique is based around four main components:
Bothwell et al (1987) tested various participants for their level of neuroticism (how much of a worrier). They then witnessed a ‘crime’ and had to identify the culprit from an ID parade. When exposed to low levels of stress the participants high in N (worriers) tended to out-perform the ones low in N. However, when exposed to high levels of stress, the outcome was completely reversed with the participants scoring high on neuroticism now performing significantly worse.
High stress + High neuroticism = Low recall
Weapons focus
In some ways related to anxiety, it isn’t really surprising that faced with a knife or gun toting maniac you’re most likely be focusing you’re attention on the weapon rather than the attacker. Loftus et al 1987 got participants to listen to a squabble between two people, one sounding more violent than the other. In the quieter affair a man with greasy hands emerges holding a pen. Following the noisy, violent sounding incident a man emerges with a blood drenched knife. Participants could accurately recall the identity of the ‘pen-fiend’ on 49% of occasions but the knifeman on only 33%. In a follow up Loftus recorded eye movements and found the focus of attention was the knife, diverting attention from the identity of the perpetrator.
However, most research into weapons focus has been lab based. In real life situations there seems to be less impact than research would predict. Studies have found that the presence of a weapon has little impact on accurate identification of culprits in real-life identity parades!
EWT and Age
The relationship between age and recall of events is also more complex than may be expected. You can probably guess that the older we get the more fragile our cognitive (and other functions) so generally wrinklies tend to make less reliable eye witnesses. However, evidence also suggests that the young are prone to errors too.
Young people and EWT
Poole and Lindsay (2001) got children of varying ages (three to eight) to watch a science demonstration following which they listened to a story which contained some of the science material but also some new information. Later when they were questioned about the science demonstration it was found that they threw in some of the story as well. In a follow up they were asked to consider where they had got the information from (the demonstration or the story). The older children could mostly do this successfully but the ones in the younger age group were less able to distinguish the source of the information. Poole and Lindsay therefore concluded that since young children are poor at ‘source recognition’ they are unlikely to make for good eye witnesses.
Pozzulo and Lindsay (1998) carried out a meta analysis of identification parade studies, particularly comparing the results of different age groups. The three main findings were as follows:
1. Children below the age of five were least likely to make correct identifications when the culprit was present in the line-up
2. Children over five were just as likely as adults to identify the culprit when they were present.
3. Children up to the age of thirteen were more likely than adults to make an identification when the culprit was NOT present in the line-up.
Conclusion
It seems that younger children are far more prone to suggestion than adults. Possible reasons for this may include:
1. They may yield to social pressure, especially when questioned by someone much older than themselves
2. They continue to believe in their distorted recall because of deficits in their cognitive abilities. They continued to make false statements even after they had been told they were making mistakes.
The cognitive interview (CI)
This was based largely on the work of Elizabeth Loftus and other psychologists, following their theoretical work into memory and EWT. Forensic psychologists combined various ideas and designed a more effective way of questioning witnesses that has been shown to produce more reliable recall of events. Fisher and Geiselman (1992) designed the cognitive interview.
The technique is based around four main components:
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Report everything: It encourages witnesses to report all detail that they can remember regardless of how trivial it may appear
Context reinstatement: It tries to recreate the scene of the incident in the mind of the witness, this includes the sights, sounds and smells but also crucially it attempts to model the emotions and feelings of the person at the time. This is based on the concept of cue dependent memory!. Recall in reverse order: It encourages witnesses to recall events in different orders, for example starting half way through a sequence of events and then working backwards Recall from a different perspective: It encourages witnesses to view the scene as others present may have seen it, for example as other witnesses, the victim or the perpetrator may have seen the incident. |
Points one and two are designed to reinstate context. They get the witness to mentally revisit the scene and mentally reconstruct the incident in their mind.
Evidence suggests that we are more likely to recall information if it is in a similar context to when it was first experienced or learned, so putting ourselves in a similar state of mind should aid recall. Points three and four are based on the idea that once a memory has been stored there is more than one way of getting at it or retrieving it. If one route fails then try another. So if working through from start to finish hasn’t worked try to accessing the memory by sneaking up on it from a different angle e.g. backwards |
Evidence for the cognitive interview
Geiselman et al (1985) got participants to watch a video of a violent crime. A few days later they were interviewed in one of 3 ways: standard police interview, cognitive interview or under hypnosis. The cognitive interview was found to trigger the most accurate recall.
Note: hypnosis is not as effective as films would lead us to believe (the so-called Hollywood effect). Witnesses often do recall more under hypnosis and are more confident in their recall. Unfortunately much of what they recall is inaccurate. Additionally, their confidence in what they recall can be very influential in court room situations, particularly with jurors so is doubly dangerous.
Kohnken et al (1999) carried out a meta-analysis of 53 other studies and found that the CI could elicit an average of 34% more detail than the standard interview and crucially without the loss of accuracy you get with hypnosis.
Interestingly, when the four components of the interview are used individually, e.g. recall in a different order, there is little gain over the standard interview. It’s only when two or more components are used that there is significant improvement in recall. Milne and Bull (2002). The report everything and context reinstatement combinations appear most effective.
But: it is difficult to compare studies carried out in different countries and even between different police forces within a country since there are now so many variations on the CI. For example in the UK the Merseyside force use pretty much the original Fisher and Geiselman design whereas Thames Valley Police (Morse and Lewis no doubt) tend to drop the ‘reinstating context.’
One criticism of the technique is that it tends to be too time-consuming in practice.
Young children seem to find the instructions confusing and as a result produce less reliable recall than with standard police interviews. Geiselman (1999) recommends that the CI is only used on children aged eight and over.
Enhanced cognitive interview
There is a slightly modified version in which, for example, interviewers use ‘open’ rather than ‘closed’ or ‘leading questions’ and are encouraged to follow the witnesses train of thought rather than get them to recall incidents in chronological order.
Using this enhanced cognitive interview method Miami Police (*Crockett and Tubbs no doubt), reported an increase of 46% in amount of detail recalled by witnesses, where corroborative evidence was available 90% of this additional testimony was shown to be accurate.
*Note Crockett and Tubbs are not researchers, so please do not use their names in answers!!!! Anybody seen re-runs of “Miami Vice?”
Geiselman et al (1985) got participants to watch a video of a violent crime. A few days later they were interviewed in one of 3 ways: standard police interview, cognitive interview or under hypnosis. The cognitive interview was found to trigger the most accurate recall.
Note: hypnosis is not as effective as films would lead us to believe (the so-called Hollywood effect). Witnesses often do recall more under hypnosis and are more confident in their recall. Unfortunately much of what they recall is inaccurate. Additionally, their confidence in what they recall can be very influential in court room situations, particularly with jurors so is doubly dangerous.
Kohnken et al (1999) carried out a meta-analysis of 53 other studies and found that the CI could elicit an average of 34% more detail than the standard interview and crucially without the loss of accuracy you get with hypnosis.
Interestingly, when the four components of the interview are used individually, e.g. recall in a different order, there is little gain over the standard interview. It’s only when two or more components are used that there is significant improvement in recall. Milne and Bull (2002). The report everything and context reinstatement combinations appear most effective.
But: it is difficult to compare studies carried out in different countries and even between different police forces within a country since there are now so many variations on the CI. For example in the UK the Merseyside force use pretty much the original Fisher and Geiselman design whereas Thames Valley Police (Morse and Lewis no doubt) tend to drop the ‘reinstating context.’
One criticism of the technique is that it tends to be too time-consuming in practice.
Young children seem to find the instructions confusing and as a result produce less reliable recall than with standard police interviews. Geiselman (1999) recommends that the CI is only used on children aged eight and over.
Enhanced cognitive interview
There is a slightly modified version in which, for example, interviewers use ‘open’ rather than ‘closed’ or ‘leading questions’ and are encouraged to follow the witnesses train of thought rather than get them to recall incidents in chronological order.
Using this enhanced cognitive interview method Miami Police (*Crockett and Tubbs no doubt), reported an increase of 46% in amount of detail recalled by witnesses, where corroborative evidence was available 90% of this additional testimony was shown to be accurate.
*Note Crockett and Tubbs are not researchers, so please do not use their names in answers!!!! Anybody seen re-runs of “Miami Vice?”