Pozzulo et al. (Line-Ups)

This study needs two pieces of background most textbooks compress.

1. Memory is reconstructive — and eyewitnesses can be wrong. We do not store events like a video; we rebuild memories at retrieval, filling gaps with expectations (schemas). This makes eyewitness testimony fallible, which matters hugely in the justice system because mistaken identifications can convict innocent people.

2. Two kinds of line-up — and two kinds of correct answer.

• A target-present line-up contains the real culprit. The correct response is a correct identification (pick the culprit).
• A target-absent line-up does not contain the culprit (the real culprit isn't a suspect). The correct response is a correct rejection — saying "the person is not here."
• A false positive is choosing someone when the target is absent — a wrong, potentially dangerous identification.

3. Why might children be worse — cognitive or social?

• A cognitive explanation: children have weaker memory, so they cannot recognise the face.
• A social explanation: children feel social pressure to choose someone (they think they're supposed to pick) — a response bias, not a memory failure. Pozzulo's clever design distinguishes these: if children recognise cartoon faces well (familiar, easy to encode) but still fail target-absent line-ups, the problem is social, not cognitive.

4. The 'elimination' idea. Child-friendly procedures (e.g. eliminating faces step by step, and explicitly allowing "not here") aim to reduce the social pressure that causes false positives.

Psychology being investigated: false positive responses and eyewitness testimony.

Background. Children are increasingly called as eyewitnesses, yet research shows they make more false positives than adults — especially when the culprit is not in the line-up. Understanding why matters for justice: is it that children can't remember the face (cognitive), or that they feel they must pick someone (social)?

Aim. To investigate the factors that cause children's higher false-positive rate in line-ups — in particular, to test whether using familiar cartoon faces (vs human faces) and comparing target-present with target-absent line-ups can reveal whether the cause is cognitive (memory) or social (response bias).

Sample: 59 children aged 4–7 (from a university-based laboratory school) and 53 adults (undergraduates).

Design (this is examined a lot):

• Age (children vs adults) = independent measures (you can't make a person both).
• Stimulus type (cartoon vs human) = repeated measures (everyone saw both).
• Target presence (target-present vs target-absent) = repeated measures.

Procedure:

1. Participants watched short video clips of two cartoon characters (Dora the Explorer and 'Go, Diego, Go!') and two human characters.
2. After a short filler task (a delay), each participant was shown a line-up for each character. The line-up was either target-present (the character was included) or target-absent (a similar-looking foil replaced the character).
3. Child-appropriate line-up procedures were used (clear instructions that the person might not be there).
4. The researchers recorded correct identifications (in target-present line-ups) and correct rejections (in target-absent line-ups), and so the false-positive rate.

(Figures are approximate proportions — quote the pattern confidently and a figure where you can.)

• Target-present (correct identification). For cartoon characters, children and adults both did well (high correct ID). For human characters, adults tended to identify better than children.
• Target-absent (correct rejection) — the key result. Adults correctly rejected (said "not here") far more often than children. Children made many more false positives, picking a foil when the target was absent — especially for human faces (e.g. children's correct rejection ≈ 0.45 vs adults ≈ 0.74).
• Effect of cartoon faces. Using familiar cartoon faces improved children's performance and narrowed the gap, but did not close it — children still made more false positives than adults.

Interpretation: since children could recognise faces (especially cartoons) reasonably well, their target-absent failures are unlikely to be purely a memory problem — pointing to a social cause (pressure to choose).

• Children make more false positives than adults, and the difference is largest in target-absent line-ups — i.e. children find it hard to say "the person is not here."
• Because children performed well at recognising (especially cartoon) faces, the problem is not simply weaker memory. It reflects a social factor — children feel pressure to choose someone (a response bias).
• Stimulus familiarity (cartoons) and better line-up procedures can reduce but not fully eliminate children's false positives.
• Application: police should use child-appropriate line-up procedures (e.g. elimination line-ups that make 'not here' an easy, acceptable answer) to improve the reliability of child eyewitnesses.

Strengths

• High control / standardised lab experiment with a clever design (cartoon vs human, target-present vs absent) → can infer cause and effect and is replicable.
• Real-world application — directly informs how police should run line-ups with child witnesses (e.g. elimination procedures).
• Quantitative data (correct ID / rejection rates) allow clear comparison between children and adults.

Weaknesses

• Low ecological validity — watching short video clips (including cartoons) is nothing like witnessing a real crime, which involves stress, surprise and real consequences. Memory under stress may differ.
• Generalisability — a specific age range (4–7) and undergraduate adults; the cartoon stimuli are particular to children's culture.
• The cartoon advantage may be familiarity, not a fair comparison — children already know Dora/Diego, so cartoon and human faces aren't perfectly matched for difficulty.

Issues & debates (named-issue gold)

• Use of children in psychological research: parental informed consent was needed; children must be protected from distress and have the right to withdraw — but using children is essential to study child eyewitnesses.
• Application to everyday life: improving justice through better line-up procedures.
• Individual vs situational: the cause identified is situational (social pressure of the line-up), not an individual memory flaw.