🔍 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 sterile lab to looking at something critically important in forensic contexts: Eyewitness Testimony (EWT).
Why do young children frequently identify an innocent person in a line-up? Is this error due to cognitive memory failure, or social pressure to make a choice? This chapter explores how age and line-up conditions impact identification accuracy.

1. Psychology Investigated: Eyewitness Testimony (EWT)

The Cognitive Context

The Cognitive Approach views memory as an information processing system (encoding, storage, and retrieval). Eyewitness testimony relies heavily on retrieval (accessing stored memory traces).

This study investigates key cognitive and social factors relating to identification line-ups:

  • Eyewitness Testimony (EWT): The memory report given by an eyewitness to identify a culprit in a line-up.
  • Target-Present (TP) Line-up: A line-up containing the actual target/culprit among fillers.
  • Target-Absent (TA) Line-up: A line-up containing only innocent foils/fillers where the correct response is rejection ('not there').
  • False Positive Response: Identifying an innocent person from a target-absent line-up rather than rejecting the line-up.

Did you know? Young children often make false positive identifications in target-absent line-ups. Psychologists study whether this occurs because children lack the cognitive ability to discriminate faces or because they feel a social obligation to choose someone when tested by an adult.

Key Takeaway

Pozzulo et al. investigated whether young children's high false positive rate in target-absent line-ups is due to cognitive factors (memory limitations) or social factors (demand characteristics/compliance with authority figures).

2. Background and Aims

Background: Why focus on Children?

Prior research showed that children perform similarly to adults in target-present line-ups (recognising a culprit when they are there). However, in target-absent line-ups, children make significantly more false positive identifications than adults.

To test whether children have a cognitive deficit in facial recognition or simply experience social pressure to pick someone, Pozzulo et al. used familiar cartoon characters alongside human targets. If children's errors are purely cognitive, they should still make false positives with familiar cartoon faces; if the error is social/contextual, familiarity should alter their performance.

Aim(s) of the Study

To test whether young children are more prone to making false positive identifications in target-absent line-ups compared to adults, and to examine whether this tendency occurs across both human faces and familiar cartoon characters.

3. Methodology and Procedure

Research Method: Laboratory Experiment

The study used a laboratory experiment with a mixed factorial design:

  • Independent Measures IV: Age group (Young Children vs. Adults).
  • Repeated Measures IVs: Line-up condition (Target-Present vs. Target-Absent) and Stimulus type (Cartoon characters vs. Human targets).
  • Dependent Variable (DV): Identification decision rate (correct identification, false positive identification, or correct rejection).

Sample and Participants

The study included a total sample of 112 participants divided into two age groups:

  • Young Children: 59 children aged 4–7 years (mean age 4.98 years), recruited from preschools and private schools.
  • Adults: 53 adults aged 17–30 years (mean age 20.54 years), recruited from an introductory psychology participant pool.

Procedure (Step-by-Step)

Step 1: Video Exposure

Each participant watched 4 short video clips:

  • 2 Cartoon Videos: Featuring familiar characters (e.g., Dora the Explorer, Go, Diego, Go!).
  • 2 Human Target Videos: Short clips showing unfamiliar humans performing neutral actions (e.g., a female brushing her hair, a male putting on a coat).
Step 2: Line-up Presentation

Following each video clip, participants completed a simultaneous photographic line-up consisting of 4 photos presented together, along with a 5th option (a silhouette/blank card representing 'not present').
Participants were instructed that the person from the video 'may or may not be there' and that they could point to the silhouette if the target was absent.

Across the 4 trials for each participant:

  • 1 Cartoon trial was Target-Present (TP), 1 Cartoon trial was Target-Absent (TA).
  • 1 Human trial was Target-Present (TP), 1 Human trial was Target-Absent (TA).
Step 3: Response Recording

Participant choices were recorded quantitatively as correct identifications (in TP line-ups), false positive selections (in TA line-ups), or correct rejections (in TA line-ups).

4. Results and Conclusions

Main Quantitative Findings

  • Target-Present Line-ups (TP):
    • Cartoon condition: Both children and adults achieved ceiling performance (~99% correct identification). This proved children understood the task and had the cognitive ability to match faces to memory.
    • Human condition: Adults achieved higher correct identification rates than children.
  • Target-Absent Line-ups (TA):
    • Human condition: Children had a significantly lower correct rejection rate (and a much higher false positive rate) compared to adults (correct rejection: children ~0.45 vs. adults ~0.70).
    • Cartoon condition: Children performed better on cartoon TA line-ups than human TA line-ups, but adults still achieved higher correct rejections.

Conclusions

Because children achieved near-perfect accuracy in target-present cartoon line-ups, their higher false positive rate in human target-absent line-ups is not simply due to a general cognitive inability to process line-ups. Instead, when faced with unfamiliar human faces in an absent line-up, children experience social demand characteristics and a cognitive bias to select someone rather than reject the line-up.

5. Evaluation (Strengths and Weaknesses)

✅ Strengths

High Standardisation and Control: The laboratory experiment controlled exposure times, video stimuli, line-up layout (4 photos + 1 silhouette), and instructions, ensuring high internal validity and replicability.
Effective Control Condition: Using familiar cartoon characters allowed researchers to establish baseline cognitive competence, ruling out the explanation that children simply do not understand line-up rules.
Application to Everyday Life: Informs police line-up protocols, demonstrating that young child witnesses need specific protective procedures to avoid wrongful accusations in target-absent conditions.

❌ Weaknesses

Low Ecological Validity: Watching brief video clips of non-violent acts (brushing hair, putting on a coat) in a quiet room lacks the emotional arousal, stress, and fear associated with witnessing a real-life crime.
Social Desirability and Demand Characteristics: Children may feel social pressure from an adult experimenter to make an active choice, leading to inflated false positive responses.

6. Issues and Debates

Application to Everyday Life

The findings are crucial for the legal system: police must exercise caution when relying on child eyewitness identification. Protocols must emphasise that the perpetrator might not be in the line-up, or use specialised child-friendly rejection mechanisms (e.g., blank silhouette options, mystery-man protocols).

Individual versus Situational Explanations

The study provides evidence for both: Individual differences (age-related cognitive developmental stages) influence face processing, while Situational factors (target-present vs. target-absent conditions, cartoon vs. human targets, and social testing context) strongly determine false positive rates.

Use of Children in Psychological Research

Working with children aged 4–7 required careful ethical considerations, including informed parental consent, child assent, age-appropriate video content to prevent distress, and ensuring children felt comfortable exercising the right to withdraw.

Key Takeaway Summary

Pozzulo et al. (2011) showed that young children can accurately identify familiar faces in target-present line-ups, but they make significantly more false positive errors than adults in target-absent human line-ups due to cognitive and social pressures to make a selection.