it's a man freed this past spring after being wrongfully in prison for two decades and spent decades in prison for a crime she did not commit and spent half of his life in prison for the murder of Marcus Boyd has been in prison since he was 14 years old after police said he had confessed to the murders of four people teenagers who were eventually convicted even though none of them did it [Music] hey everyone welcome back to parity mind in this video we're exploring eyewitness testimony an eyewitness is someone who has seen something happen often in relation to a crime and can give a first-hand description of it one factor that can affect the accuracy of eyewitness testimony is misleading information this is where someone is an eyewitness to a crime but before they are asked to recall what happened they are exposed to new information how will this affect the original memory very importantly for you to know is that Under The Heading of misleading information come two parts firstly leading questions and secondly post-event discussion let's explore leading questions first [Music] leading questions are questions which prompt or encourage an answer that is wanted by the person asking the question this might be the police or from a lawyer in court this brings us to this woman a psychologist by the name of Elizabeth Loftus who has become known for her years of research exploring eyewitness testimony one of her studies back in 1974 with fellow psychologist John Palmer explored the impact of the way that language used in questions could alter memory in their first experiment 45 American students from the University of Washington saw a series of films containing traffic accidents they were then asked to describe what had happened just like an eyewitness but they were also asked some more specific questions with the critical question being about how fast were the cars going when they bumped into each other and there were five versions of this ranging from contacted to smashed you can see how the the words vary in the level of intensity that they suggest about the crash so what did they find here's a graph showing the speed estimates from the participants for each of the five conditions here we can see that when the verb smashed was used it led to a much higher estimate of speed than the other words notice how simply changing one word in a question can lead to markedly different responses it shows how eyewitness testimony can be affected by misinformation in their second experiment 150 students were shown a one minute film that ended with a multiple car accident they were then given a questionnaire this first asked them to Simply describe their accident in their own words and then they were given some specific questions to answer the critical question was once again about the speed of the vehicle but this time there were three versions 50 participants were asked about how fast was the car going when they smashed into each other 50 participants were asked about how fast was the car going when they bumped into each other and 50 participants were not asked any question about speed they were the control group one week later the participants were then asked a series of questions about what they had watched the week before hidden amongst a bunch of other questions was this critical question did you see any broken glass of course there was no broken glass in the original film but the researchers predicted that participants would be more likely to say there was in the condition where they were asked if the cars smashed into each other and that's exactly what they found this research further demonstrates how the accuracy of memory can be affected by information and specifically leading questions [Music] now one of the main strengths of the research that has been conducted into misleading information such as with the work of Loftus and Palmer is that it has real-world practical application for police and lawyers for example a technique for interviewing eyewitnesses has been developed known as the cognitive interview one part of this interview has been directly shaped by the knowledge of how leading questions can negatively influence the accuracy of recall to combat this the cognitive interview requires interviewers to specifically avoid the use of such questions and instead asks participants to report everything this gives eyewitnesses the opportunity to recall all the information that occurred without filtering it for relevance with interviewers simply asking open-ended questions like what happened next research by concanital in 1999 found that as a result of these changes the cognitive interview provided more accurate information than a typical standard interview therefore this demonstrates the value of research into misleading information in how it improved the accuracy of eyewitness testimony [Music] a second area of misleading information is called post-event discussion imagine you and I witness to a crime but you're not the only witness and so immediately after the event you're in a conversation with the other Witnesses because you've both witnessed something very significant something which you can both relate to post event discussion is the idea that Witnesses of the same event discuss the details of a crime after it has occurred but can this cause problems with your memory to explore this psychologist Fiona Gabbert conducted a study with colleagues in 2003. the participants watched a short film where a girl entered a university office to return a borrowed book however there were two video clips of this film both video clips contained exactly the same sequence of events they were just filmed from different angles just like two different Witnesses viewing the same event this meant that different features of the event could only be seen from each angle only witness a could read the title of the book the girl was carrying and only witness how you could see that she throws a piece of paper into the bin when she leaves the room on the other hand only witness B could see the girl checking the time in her watch and only witness B can see her committing the crime of sliding a 10 pound note out of a wallet and putting it into her own pocket after watching the video the participants then completed a questionnaire on their recall of what happened they either did this individually which was the control condition or with another participant where post-event discussion would take place this was the co-witness condition they found that 71 percent of Witnesses in the co-witness condition reported information that they had gathered from the other witness and shockingly sixty percent of participants in the co-witness group reported that the girl was guilty of a crime even though they had not actually witnessed it taking place in conclusion we can see from this study that post-event discussion can info recall of a crime and show another way that misinformation can influence the accuracy of eyewitness testimony [Music] now let's discuss this research on the one hand the research by a Lotus and Palmer and gabatital can be praised for being conducted in highly controlled experimental settings this enables the careful control of extraneous variables so that cause and effect can be established whether that's one single verb affecting the estimate speed or what angle the video was from and whether they had a co-witness to discuss the events additionally this high level of control enables the research to be replicated to check the reliability of the findings therefore the quality of This research strengthens the argument for how misleading information can affect eyewitness testimony on the other hand one of the main drawbacks to this type of research is that they are artificial studies into eyewitness testimony for example both Loftus and Palmer and Gabbert showed participants video recordings of events this is a problem because the participants in the studies are not actually eyewitnesses to real crimes the level of anxiety and seriousness that that would be present for an eyewitness to a real event is simply missing in fact research by Foster hotel in 1994 found that eyewitnesses were more accurate when they believed that the video they were watching was of a real life robbery and that their responses would influence the trial studies such as lofted and Palmer and Gabba lack this level of realism all this points to problems with the ecological validity of the research and by extension raise these questions about how much this research provides intight into the role that misleading information could have an eyewitness testimony additionally one of the criticisms specifically with Loftus and Palmer's research relates to the sample this is because their participants were 45 American University students who are not very representative of the general population particularly in a piece of research into driving with their limited years if any of driving how insightful and accurate would their estimates of speed be perhaps a more well-practiced driver may have been able to draw on their years of experience to interpret the situation and information available in the video to estimate the speeds of the car in a more precise way therefore this sampling issue undermines the research and further raises questions about the role of misleading information on eyewitness testimony so bear in mind the dangers of misleading information do check out the work of the Innocence Project which is linked for you below where you can read about other cases where people were convicted of crimes they didn't commit however misleading information is only one factor that can affect the accuracy of an eyewitness another crucial area for you to understand is the role of anxiety including something called weapons Focus we're going to explore that in the next video which you can watch by clicking on the screen now I hope you found this video helpful and we'll see you in the next one [Music] foreign