There has been much debate about the accuracy and reliability of eyewitness testimony. In particular, many studies have investigated the effects of presenting eyewitnesses with misleading information either before or after the witnessed event. There is a great deal of evidence to suggest that subsequent questioning, and the use of ‘leading questions’ can influence the memory of eyewitnesses.
Aim The aim of the study was to replicate the study of Loftus and Palmer (1974), in which they investigated the effects of leading questions on their participants’ memory of a particular event, in this case a car crash. Method After conducting a pilot study, thirty university students were randomly allocated to different groups: bumped, collided or smashed. Each group was shown the same video of a car crash and were subsequently asked to fill out a questionnaire. All questions were the same for each group, apart from one question where the verb was changed, “How fast did you perceive the car to be travelling when it (bumped/collided/smashed) into the other car?”
The analytical comparisons of the ANOVA showed that there was no significant difference between the mean estimations in the bumped and collided conditions, F (2,9) = 1.20, p<0.05, and there was a significant difference for the collided and smashed groups, F (2,9) = 5.79, p>0.05. By looking at the mean results for each condition, it was clear to see that when the verb ‘smashed’ was used, the estimation of speed was highest. It was lowest when the verb ‘bumped’ was used.
Conclusions The results of this report are consistent with the hypothesis that when eyewitnesses are asked misleading questions after an event, it can cause an alteration of the original memory of the event. The findings would suggest that eyewitness testimonies might not always be reliable. Introduction Within the criminal justice system many methods are adopted to investigate information about a crime or criminal, such as, forensics, cross examination, interviews, identification parades and eye witness testimony. Criminal psychology looks into the effectiveness of these methods employed and psychological research has been known to lead to changes to the way in which the criminal justice system operates.
One area of focus for criminal psychologists is that of eye witness testimony and its level of reliability. It has been of great concern to what extent the evidence from eye witnesses can be depended upon when convicting a criminal. Eyewitness testimony is the ability to recollect an event after it has occurred and give a statement of what has been recalled in a court-room situation. This method is frequently used within the criminal justice system for the prosecution of individuals: therefore the accuracy of an eyewitness testimony is invaluable.
However, reporting details of numerical importance (e.g. speed and distance) in a situation like this has been found to be very inaccurate (Bird and Whipple, 1927, 1909). Many false imprisonments have been caused by false testimonies and faulty eyewitness reports. This study demonstrates the inaccuracy of an eyewitness’ judgement of speed – this factor is considered to be particularly hard to judge. This is part of the reason for such wide variations in eyewitness reports of car accidents.
A key question regarding eyewitness testimony is: ‘which variables can cause such inaccurate recollections of events?’ one such variable is thought to be leading questions, “One that, either by its form or content, suggests to the witness what answer is desired it leads him to the desired answer” (Loftus and Palmer, 1974). In other words, the way a question is formed can have an effect on the response given because the individual has been influenced by the question.
In 1974 Loftus and Palmer conducted a study to test their theory; that leading questions can have a significant affect upon later recall especially that of eye-witness testimony. Their study involved participants watching a short video of a car crash. Subsequent questions were then asked, including estimating the speed of the vehicle involved in the accident. The question was “about how fast was the car travelling when it smashed into the other car?” Certain participants received this question, others had the same question but the word ‘smashed’ was replaced with either contacted, hit, bumped or collided. Results revealed a correlation; the more extreme the verb (smashed), the higher the estimated speed. In fact, the mean estimated speed of the ‘contacted’ group was 32mph, whereas the ‘smashed’ condition was estimated at 42mph.
Such results can be interpreted in two ways. A participant may have been undecided between two speeds and the presence of the word ‘smashed’ may bias their opinion toward the higher speed. Or, and slightly further fetched is the idea that the form of the question could alter a participant’s memory representation of the incident. Our study aimed to reinforce and support Loftus’ and Palmer’s theory producing a similar trend in results, with the hope of reinforcing further to the criminal justice system to what extent eye-witness testimonies are unreliable. The null hypothesis was that the wording of the question will have no effect on the answer given. The alternative hypothesis is that the more extreme the verb used is, the higher the estimation of speed reported will be.
Method Participants 30 non-psychology students from Keele University were selected at random from an opportunity sample to take part in this experiment. Within this experiment were 16 females and 14 Males. The mean age of the participants was 21.86 (SD= 15.75) Materials During the experiment the materials used consisted of a video that can be obtained from the following website, this video was shown to the participants and stopped after the first 9 second of showing, and a questionnaire consisting of 7 questions based on the video for participants to answer, a copy of the questionnaire used can be found in the appendix.
Design Participants were randomly assigned to each of the three conditions upon entering the experimental room. Participants only provided data for one of the three conditions meaning an independent design was employed. Participants were tested separately so as conferring between participants did not occur, they were also requested not to speak of the experiment to any other potential participants upon completion of the experiment.
The independent variable in this study was the 4th question “How fast did you perceive the car to be travelling when it…into the other car?” in the questionnaire and the word used either, “smashed”, “bumped” or “collided”. The DV was the response of the participant to the question. The entire test was conducted under experimental conditions. Procedure Participants were separated and one by one entered the experiment room with the experimenter to take part in the study. Participants were then asked to sign a consent form (see appendix) and asked if they had any further questions, all participants were informed of their right to withdraw themselves or their data from the experiment at any time, they were also aware that participation was 100% voluntary. After the consent form was signed the experiment began and all noises and visual distractions were blocked from the experiment room by closing doors, windows and curtains etc.
Once seated approximately 2 metres away from the computer participants were talked through the procedure by the experimenter and asked once again if they had any questions or wished to withdraw from the study. Only the experimenter and the participant were in the room. The experimenter then started the video clip and stopped it after 9 seconds. The participant was then given a questionnaire. The participant read the sheet and answered the questions by writing on the sheet. The questionnaire was then collected by the experimenter and gave the participant a debriefing sheet explaining the purpose and aim of the experiment; participants were once again given the opportunity to withdraw their data and information.
This experimental procedure was carried out 30 times with 30 different participants. 3 different questionnaires were distributed (10 of each) between the participants at random without them knowing this. All questionnaires were identical apart from one word in one question. The question “How fast did you perceive the car to be travelling when it…into the other car?” varied and in the first condition the questionnaire asked “How fast did you perceive the car to be travelling when it bumped into the other car?”
In the second condition the questionnaire asked “How fast did you perceive the car to be travelling when it collided into the other car?” and in the third condition the questionnaire asked “How fast did you perceive the car to be travelling when it smashed into the other car?” These three words are different in severity smashed being the most severe and bumped being the least. It was predicted that the more severe the word used the higher the speed estimated by the participant.