Psychology: Memory Bias and Eyewitness Testimony
How memory errors can affect what witnesses report
Psychology: Memory Bias and Eyewitness Testimony
How memory errors can affect what witnesses report
Psychology - Grade 9-12
- 1
Define memory bias in your own words. Then give one example of how memory bias could affect a witness describing a crime.
Focus on how memory can be shaped by beliefs, expectations, or later information.
Memory bias is a systematic error in remembering that changes how a person recalls an event. For example, a witness who expected the robber to be angry might later remember the robber's face as more threatening than it actually was. - 2
A witness sees a car accident. Later, an interviewer asks, "How fast was the car going when it smashed into the truck?" Explain why this question could change the witness's memory.
Think about how word choice can suggest an answer.
The question is leading because the word "smashed" suggests a severe crash. This wording could make the witness estimate a higher speed or remember the accident as more violent than it was. - 3
Explain the misinformation effect and describe one way it can occur in an eyewitness situation.
The misinformation effect happens when information learned after an event changes a person's memory of the original event. It can occur when a witness hears another witness mention a detail, such as a red backpack, and later mistakenly remembers seeing that detail. - 4
A student says, "Eyewitnesses are always reliable because they were actually there." Write a response that agrees or disagrees using evidence from psychology.
Separate perception at the time of the event from memory later.
I disagree because being present does not guarantee accurate memory. Eyewitness memory can be affected by stress, attention, leading questions, stereotypes, the passage of time, and post-event information. - 5
Look at the diagram of three memory stages: encoding, storage, and retrieval. For each stage, name one problem that could reduce the accuracy of eyewitness testimony.
During encoding, the witness may not pay attention to important details. During storage, the memory may fade or be changed by new information. During retrieval, a leading question or pressure from police may influence what the witness reports. - 6
A witness briefly sees a suspect at night from across a parking lot. List two factors that might make the witness's identification less accurate and explain why.
Consider both the viewing conditions and the amount of attention available.
Low lighting could make it harder to see facial features clearly. Distance could also reduce accuracy because the witness may not have seen enough detail to form a strong memory. - 7
Explain why high confidence does not always mean high accuracy in eyewitness testimony.
High confidence does not always mean high accuracy because confidence can be increased by feedback, repeated questioning, or pressure to choose someone. A witness can become very sure about a memory that is still mistaken. - 8
A police officer tells a witness, "Good job, you picked the same person another witness picked." Explain how this feedback could affect the witness.
Think about the difference between accuracy and confidence.
This feedback could increase the witness's confidence in the identification even if the identification is wrong. It may also make the witness remember their original view of the suspect as clearer than it really was. - 9
In a lineup, the suspect is the only person wearing a bright red jacket that was mentioned in the crime report. Explain the problem with this lineup and how it could be improved.
The lineup is biased because the suspect stands out based on the clothing detail. It could be improved by having all lineup members wear similar clothing or by removing the distinctive jacket from the lineup. - 10
Describe the difference between a simultaneous lineup and a sequential lineup. Explain why a sequential lineup may reduce some false identifications.
Focus on relative judgment versus judging each person separately.
In a simultaneous lineup, the witness sees all lineup members at the same time. In a sequential lineup, the witness sees one person at a time. A sequential lineup may reduce false identifications because witnesses are less likely to choose the person who looks most like the culprit compared with the others. - 11
A witness is asked to identify a suspect from a group of photos. The real culprit is not included. Explain why this situation can lead to a false identification.
If the real culprit is not included, the witness may still feel pressure to choose the person who looks most similar to their memory. This can lead to an innocent person being falsely identified. - 12
Explain how stress during a crime might affect attention and memory. Include both a possible helpful effect and a possible harmful effect.
Moderate stress and extreme stress can have different effects.
Stress might help memory for central details because the event feels important and emotionally intense. However, high stress can harm memory for details because attention may narrow and the person may have trouble encoding everything accurately. - 13
A robbery victim focuses on the weapon during the crime and later cannot clearly describe the robber's face. Identify this effect and explain it.
This is the weapon focus effect. The victim's attention is drawn to the weapon because it is threatening, so less attention is available for encoding the robber's face and other details. - 14
A witness says, "I remember the suspect had a tattoo because I read in the news that police were looking for someone with a tattoo." Explain what source monitoring error might be involved.
Source monitoring means keeping track of where a memory or detail came from.
A source monitoring error may have occurred because the witness may confuse where the information came from. They might remember the tattoo detail as something they saw at the crime scene when it actually came from the news. - 15
Write two recommended practices that investigators can use to make eyewitness evidence more reliable. Explain why each practice helps.
Investigators can use neutral, non-leading questions so witnesses are less likely to be influenced by suggestion. They can also use double-blind lineup procedures, where the administrator does not know who the suspect is, to prevent unintentional cues.