Factors affecting eyewitness testimony: misleading information

What is eyewitness testimony?

• the ability of people to remember the details of events, ie- accidents and crimes, which they themselves have observed

• Accuracy of EWT can be affected by factors ie- misleading info, leading questions and anxiety

What is misleading info?

• incorrect info given to the eyewitness usually after the event (hence often called ‘post-event info’)

• Can take many forms, ie- leading info and post-event discussion between Co-witnesses and/or other people

What is a leading question?

• a question which, because of the way it’s phrased, suggests a certain answer

• Eg- ‘was the knife in the accused’s left hand?- this suggests the answer is ‘left hand’

What is post-event discussion?

• occurs when there is more than one witness to an event

• Witnesses may discuss what they have seen with Co-witnesses or with any other people

• This may influence the accuracy of each witness’s recall of the event

Who conducted an experiment on how leading questions affect eyewitness testimony?

Loftus and Palmer (1974)

What was the procedure of Loftus and Palmer’s experiment on leading questions?

• they arranged for participants to watch film clips of car accidents and then gave them questions about the accident

• In the critical question (a leading question) participants were asked to describe how fast the cars were travelling, eg- how fast were the cars going when they hit each other?

• Leading question because ‘hit’ suggests they speed the car was going

• 5 groups- each given different verb- hit, contacted, bumped, collided, smashed

What were the findings of Loftus and Palmer’s experiment on leading questions

• mean estimated speed calculated for each participant group

• Contacted- resulted in mean estimated speed of 31.8mph

• Smashed- mean was 40.5mph

• Leading question biased eyewitness recall of an event

Why do leading questions affect EWT? (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 a participant gets a leading question using ‘smashed’ this encourages them to choose a higher speed estimate

Why do leading questions affect EWT? (Substitution explanation)

• Loftus and Palmer conducted another experiment- supported substitution explanation

• The wording of a leading question actually changes the participants memory of the film clip

• This was demonstrated because participants who originally heard ‘smashed’ later were more likely to report seeing broken glass (there was none) than those who heard ‘hit’- the critical verb altered their memory of the incident

Who conducted a study on how post-event discussion affects EWT?

Gabbert et al

What was the procedure of Gabbert et als study?

• they studied participants in pairs- each participant watched a video of the same crime, but filmed from different povs

• Meant that each participant could see elements in the event that others couldn’t, eg- only one of the participants could see the title of a book being carried by one woman

• Both participants then discussed what they had seen before individually completing a test of recall

What were the findings of Gabbert et als study?

• the researchers found that 71% of the participants mistakenly recalled parts of the event that they didn’t see in the video but had picked up in the discussion

• the corresponding figure in a 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- this is called phenomenon memory conformity

What did Bodner et al. find about post-event discussion?

• found that the effects of post-event discussion can be reduced if participants are warned of the effects

• Recall was more accurate for those participants who were warned that anything they hear from a co-witness is second-hand info and that they should forget it and recall their own memory of the event

What were the findings of Clifasefi et als study involving leading questions?

• later the participants completed a memory test in which a leading question asked when they had become sick from too much drinking

• the researchers found that a significant number of participants ‘recalled’ being sick due to drinking too much alcohol before they were 16

• A proportion of these participants also claimed that they now disliked certain alcoholic drinks because of this (non-existent) experience

evaluation- useful real-life applications

• strength- hugely important practical uses in the real world, where the consequences of inaccurate EWT can be very serious

• eg- Loftus believes that leading questions can have such distorting effects on memory that police officers need to be very careful about how they phrase their questions when interviewing eyewitnesses

• research into EWT is one area in which psychologists believe they can make an important positive difference to the lives of real people, ie- by improving the way the legal system works and by appearing in court trials as expert witnesses

evaluation- the tasks are artificial

• limitation of Loftus and Palmer’s study- their participants watched film clips of car accidents- very different experience from witnessing a real accident, mainly because such clips lack the stress of a real accident- there’s some evidence that emotions can have an influence on memory

• limitation as studies that use such artificial tasks may tell us very little about how leading questions affect EWT in cases of real accidents or crimes- could even be that researchers like Loftus and Palmer are too pessimistic about the accuracy of EWT- it may be more reliable than many studies suggest

evaluation- individual differences

• there’s evidence that older people are less accurate than younger people when giving eyewitness reports- eg- a research study found that people in age groups 18-25 and 35-45 were more accurate than people in the group 55-78 years

• but, all age groups were more accurate when identifying people of their own age group (own age bias)

• research studies often use younger people as the target to identify and this many mean that some age groups appear less accurate but in fact this isn’t true

evaluation- demand characteristics

• some researchers argue than many answers participants give in lab studies of EWT are the result of demand characteristics- participants usually don’t want to let the researcher down, and want to appear helpful and attentive

• so when they’re asked a question they don’t know the answer to, they guess, especially if it’s a yes/no question