Factors affecting EWT: Misleading information

• Eye witness testimony is the ability of people to remember the details of events, such as accidents and crimes, which they themselves have observed
• The effects of leading questions on the accuracy of EWT were investigated by Loftus and Palmer (1974) where participants watched a film clip of a car crash and then gave speed estimates of the cars based on the leading question of “About how fast were the cars going when they x into each other?”, with each group being exposed to a different critical verb. Those exposed to the verb “smashed” gave a speed estimate of 8.7 mph greater than those who’d heard “contacted”. Therefore, this shows that leading questions, because of the way they are phrased, suggest that there is a correct answer.
• The effects of leading questions can be explained using the idea of response bias (i.e. these questions only influence the participants to give a certain answer), whereas Loftus and Palmer’s study supports the substitution explanation (i.e. leading questions change the eyewitness’ memory of the crime), as those who’d heard the word “smashed” were more likely to report having seen broken glass 2 weeks after the crime (despite there being no broken glass) compared to those who’d heard the word “contacted”.
• Leading Q's affect responses because of: -Response bias- no real effect on memory, simply influences how a P answers a question. -Substitution explanation- the wording of a question actually changes how a person remembers an event (the information is altered before it is permanently stored)-this relates to Loftus and Palmers' experiment it shows how the leading question changed the participant's memory. Some saw broken glass when there wasn't only due to the wording.
• One weakness is that Loftus and Palmer's research lacks population validity. E.g. Loftus and Palmer's sample consists of 45 American students, so it could be argued that the experiment is culturally biased. This is a weakness because we don't know if other cultures would also be susceptible to the effects of misleading information, we are unable to conclude whether misleading information affects the accuracy of EWT in other countries.
• One strength of Loftus & Palmer's research is the application of their findings to the criminal justice system. The CJS relies heavily on the accounts of eyewitnesses and Loftus & Palmer's research highlights the danger of misleading information being used in the courtroom by lawyers, as a single misleading question can affect the accuracy of EWT. This is a strength because it can help ensure that courtrooms operate fairly and that innocent people are not convicted of crimes they didn't commit, based on inaccurate eyewitness evidence.
• A weakness with Loftus & Palmers research is that they deceived their ppts,therefore did not adhere to the code of ethics.They didn't tell their ppts the aim of their research, therefore did not abide by the BPS code of ethics. However, deception is necessary in order to obtain valid results. If they told the ppts that they were going to mislead, it could've led to demand characteristics where the ppts changed their behaviours, affecting the study. The deception was a strength to ensure the collection of data to further our knowledge into the effects of misleading info on the accuracy of EWT.
• Another strength is that Loftus and Palmers further research supports the role of misleading questions in reducing the accuracy of EWT. E.g., they showed 150 students a video of a car crash and 50 were asked the critical question with the word 'smashed', 50 with the word 'hit', and 50 were the control group, not asked anything at all. After a week the students were asked if they saw broken glass (wasn't any). Ppts in the 'smashed' condition were 2x likely to recall the memory of broken glass. This is a strength because it demonstrates misleading info (form of questioning) can distort the EWT.
• Post-event discussions describe the discussions that take place between co-witnesses after the crime has taken place, and is subject to the influence of media and TV reports on the crime, as well as participants’ pre-conceived expectations of how they would imagine the crime.
• Post event discussion:

  • Gabbert et al (2003), using a matched-pairs design, showed participants a film clip of the same crime scene, but with different details for each member. After engaging in post-event discussions with the other member of each pair, individually completing a test of recall, the researchers found 71% inaccuracy rates of information gained through such discussions, compared to a 0% control group rate who had worked alone throughout
• Conclusion of Gabbert et al's study:-witnesses go along with each other to win social approval or because they believe the other witnesses are right and they are wrong- memory conformity.