🔍 Core Study: Pozzulo et al. (2011) – The Culprit in Target-Absent Line-ups

👋 Welcome to the Cognitive Approach!

Hello future psychologists! This study by Pozzulo et al. is a perfect example of how the Cognitive Approach works in the real world. We are moving away from studying memory in a lab to looking at something incredibly important: Eyewitness Testimony (EWT).
Why do people sometimes identify the wrong person in a line-up? Is this mistake more common in children or adults? This chapter explores how age impacts our memory processes when trying to identify a criminal.

1. Psychology Investigated: Eyewitness Testimony (EWT)

The Cognitive Context

The Cognitive Approach assumes that memory works like an information processing system (input, process, output). Eyewitness testimony relies heavily on the final stage: retrieval (getting the memory out).

This study specifically investigates two key cognitive concepts relating to line-ups:

  • Eyewitness Testimony (EWT): The memory a person has of a crime or event they witnessed, often relied upon in legal proceedings.
  • False Positive Responses: A critical type of error where the witness identifies someone from the line-up who is not the person they saw (and sometimes, the culprit isn't even in the line-up).

Did you know? Research consistently shows that EWT is often flawed. Psychologists like Pozzulo aim to understand *who* is most vulnerable to memory errors and *why*.

Key Takeaway

Pozzulo et al. used the cognitive framework to investigate differences in memory reliability, focusing specifically on how age affects the likelihood of making a false positive identification when the real target is absent.

2. Background and Aims

Background: Why focus on Children?

Previous research had shown conflicting results about the reliability of child witnesses. Some studies suggested children were just as accurate as adults when the culprit was present (Target-Present Line-up). However, when the culprit was not present (Target-Absent Line-up), children seemed more likely to pick someone anyway—leading to a false positive.

Why would children do this? It may be due to a cognitive strategy (or lack thereof) where they feel pressured to choose, or they lack the ability to effectively compare the faces to their memory trace.

Aim(s) of the Study

The primary aim was to investigate the factors affecting memory for target faces in a line-up, specifically comparing how children and adults differed in their rates of making false positive responses in target-absent line-ups.

3. Methodology and Procedure

Research Method: Laboratory Experiment

The study used a laboratory experiment, which allowed the researchers to maintain strict control over variables, such as what the participants saw and whether the culprit was in the line-up.

The study employed a comparison design, looking at three age groups (the Independent Variable, IV).

Independent Variable (IV): The age of the participant.
Dependent Variable (DV): The percentage of correct identifications and false positive responses.

Sample and Participants

The study compared three main age groups, totaling 112 participants:

  • Young Children: Ages 4–6 years.
  • Older Children: Ages 7–11 years.
  • Adults: Mean age of 39 years.

The participants were obtained through an unspecified sampling technique, likely Opportunity Sampling or Volunteer Sampling from community centres and schools.

Procedure (Step-by-Step)

Pozzulo et al. conducted a series of different experiments, but the core procedure for testing target-absent line-ups involved the following steps:

Step 1: Exposure to the Target

Participants watched a short video or presentation where they saw a target face (the "culprit"). In some conditions, this was the face of a cartoon character; in other conditions, it was a human face.

Step 2: The Line-up (Target-Absent)

After a delay (retention interval), participants were presented with a sequential line-up (faces shown one after the other) or a simultaneous line-up (faces shown all at once).
Crucially, in the key condition being studied, the target face was deliberately absent. This means there was no correct answer.

Step 3: Identification and Interviews

Participants were asked to identify the person they saw from the initial viewing. Since the target was absent, a "correct" identification was impossible. Any identification made was recorded as a false positive response.
They also used interviews and questionnaires to gather qualitative data, such as asking participants how confident they felt in their choice.

Analogy: Imagine you meet a delivery driver briefly, then later you are shown a photo line-up of 6 people, none of whom were your driver. If you pick one, you've made a false positive error because you thought someone was the driver when they weren't.

Quick Review Box: The Key Setup
  • Target was Absent.
  • Task: Identify the person seen earlier.
  • Main focus: How many False Positives each age group makes.

4. Results and Conclusions

Main Quantitative Findings

The results strongly highlighted the impact of age on identification errors:

  • Adults (Best Performance): Adults were the most accurate overall and had the lowest rate of false positive responses.
  • Older Children (Intermediate): Children aged 7–11 years performed better than the younger group but still showed higher false positive rates than adults.
  • Young Children (Lowest Performance): Children aged 4–6 years had the highest rate of false positive responses in the target-absent line-ups. They were significantly more likely to choose someone even when the culprit was not present.

The Cartoon vs. Human Face Finding

The study also used cartoon characters to test whether the type of face affected memory. They found that false positive errors were high across the board for cartoons, suggesting that these identification processes are general across different stimuli.

Conclusions

The study concluded that children (especially younger ones) are substantially more vulnerable to false positive errors in target-absent line-ups than adults. This suggests that memory retrieval strategies and decision-making abilities (perhaps related to metacognition—knowing what you know) are less developed in younger witnesses.

5. Evaluation (Strengths and Weaknesses)

✅ Strengths (Making the study good)

High Control (Reliability): Since this was a laboratory experiment, the researchers had excellent control over variables. They ensured all participants saw the target for the same amount of time and that the line-up was always target-absent in the key condition. This increases the study's reliability.
Application to Everyday Life: The findings have direct and immediate applications for the criminal justice system. They suggest that legal procedures must be adapted when dealing with young eyewitnesses to minimize the risk of wrongly identifying a suspect. For example, explicitly telling the child that the culprit might not be in the line-up.

❌ Weaknesses (Limitations)

Low Ecological Validity: Participants were identifying faces of cartoon characters or unfamiliar humans in a lab setting, which has low stakes. In a real-life crime, an eyewitness would experience high stress and fear, which can drastically affect memory performance (this is known as the weapon focus effect or stress impact). The lab setting is artificial.
Potential Demand Characteristics: Especially for children, being placed in an experimental situation might create pressure to "please the researcher" or feel compelled to make a choice, even when unsure. This could inflate the rate of false positive responses.

💡 Common Mistake to Avoid

Don't confuse a *target-present* line-up (where a true positive identification is possible) with a *target-absent* line-up (where the only potential errors are false positives or correct rejections). Pozzulo focused on the high error rate in Target-Absent line-ups.

6. Issues and Debates

Application to Everyday Life (High Relevance)

This study is an excellent example of the application of psychology. The findings provide critical evidence to inform police practice and legal guidelines regarding child witnesses. It suggests that line-ups should include clear instructions that the culprit may not be present, which helps reduce the child's feeling that they "have to choose."

Individual versus Situational Explanations

Pozzulo et al. mainly support an Individual Explanation for EWT error, as the central variable determining performance was the participant's age (an individual characteristic). The study highlights cognitive differences between age groups that impact how memory is retrieved and how decision-making occurs.

Use of Children in Psychological Research

While the study provides invaluable data, researchers must ensure strict ethical guidelines are followed. Children were involved, necessitating parental consent and ensuring that the procedures (e.g., viewing a "culprit") did not cause unnecessary distress or psychological harm. The right to withdraw must also be clearly understood by the child.

Key Takeaway Summary

Pozzulo demonstrated that age is a crucial factor in the reliability of eyewitness testimony, particularly when the target is absent. This strengthens the argument that EWT procedures need modification to protect against wrongful identification, especially by young witnesses.