Introduction
Psychologist Elizabeth Loftus has been particularly concerned with how subsequent information can affect an eyewitness’s account of an event.
Her main focus has been on the influence of (mis)leading information in terms of both visual imagery and wording of questions in realtion to eyewitness testimony.
Loftus’ findings seem to indicate that memory for an event that has been witnessed is highly flexible. If someone is exposed to new information during the interval between witnessing the event and recalling it, this new information may have marked effects on what they recall. The original memory can be modified, changed or supplemented.
The fact the eyewitness testimony can be unreliable and influenced by leading questions is illustrated by the classic psychology study by Loftus and Palmer (1974) Reconstruction of Automobile Destruction described below.
Loftus and Palmer (1974) Psychology Study
Aim: To test their hypothesis that the language used in eyewitness testimony can alter memory. Thus, they aimed to show that leading questions could distort eyewitness testimony accounts and so have a confabulating effect, as the account would become distorted by cues provided in the question.
To test this Loftus and Palmer (1974) asked people to estimate the speed of motor vehicles using different forms of questions. Estimating vehicle speed is something people are generally poor at and so they may be more open to suggestion.
Procedure: Forty-five American students formed an opportunity sample. This was a laboratory experiment with five conditions, only one of which was experienced by each participant (an independent measures design).
Participants were shown slides of a car accident involving a number of cars and asked to describe what had happened as if they were eyewitnesses. They were then asked specific questions, including the question “About how fast were the cars going when they (hit/smashed/collided/bumped/contacted ) each other?”
Thus, the IV was the wording of the question and the DV was the speed reported by the participants. A week after the participants saw the slides they were asked “Did you see any broken glass?” There was no broken glass shown in the slides.
Findings: The estimated speed was affected by the verb used. The verb implied information about the speed, which systematically affected the participants’ memory of the accident.
Participants who were asked the “smashed” question thought the cars were going faster than those who were asked the “hit” question. The participants in the “smashed” condition reported the highest speeds, followed by “collided”, “bumped”, “hit”, and “contacted” in descending order.
When people were asked a week after viewing the film whether they saw any broken glass at the scene (there was none), people in the smashed group were more likely to say yes. Therefore, a leading question that encouraged them to remember the vehicles going faster also encouraged them to remember that they saw non-existent broken glass. The question appears to have modified the memory itself.
Conclusions: This research suggests that memory is easily distorted by questioning technique and information acquired after the event can merge with original memory causing inaccurate recall or reconstructive memory.
The addition of false details to a memory of an event is referred to as conflabulation. This has important implications for the questions used in police interviews of eyewitnesses.
Criticisms: The research lacks mundane realism, as the video clip does not have the same emotional impact as witnessing a real-life accident and so the research lacks ecological validity.
Further Information: http://www.holah.karoo.net/loftus.htm
