Line ups

Cognitive Approach

Core Study 3: Pozzulo et al. (Line-ups)

• Citation: Pozzulo, J., Dempsey, J., Bruer, K. C., & Sheahan C. (2011). The culprit in target-absent lineups: understanding young children's false positive responding. Journal of police and criminal psychology, 27(1), 55-62.

The Psychology Being Investigated

• Comparison between Human Memory and Computer Memory:

  • Memory systems in humans and computers are analogous in some aspects but fundamentally differ:

  • Computers generate error-free copies of memories, unless influenced by external factors like software viruses.

  • Human memory is susceptible to accidental distortion through exposure to new information after the encoding process.

  • Post-event Information: Additional details given to an eyewitness after the event can lead to 'false memories'.

  • Example of False Memories:

  • Loftus and Palmer (1974) conducted an experiment where adult participants watched a video of a car accident.

  • They found that the phrasing of questions affected participants’ speed estimates:

    • Higher estimates with the word "smashed" vs. "hit" (i.e. "How fast were the cars going when they smashed into each other?" vs. "How fast were the cars going when they hit each other?").

• Reliability of Child Eyewitness Testimony:

  • Children can witness crimes, sometimes being the only observers, necessitating assessment of their reliability as witnesses.

Key Definitions

• False Memory:

  • A stored piece of information the individual mistakenly believes is accurate, resulting from later misinformation.

• Eyewitness Testimony:

  • Evidence from someone who has witnessed a crime, utilized by the legal system.

Background of Study

• Pozzulo et al. focus on child witnesses, examining how cognitive factors like post-event information affect decision-making errors.

• Previous research (Pozzulo & Lindsay, 1997) indicated children were less likely than adults to respond with "I don't know" to questions, even when that answer was appropriate.

Issues with Line-Ups

• Line-Up Procedure in Police Work:

  • Utilized for identifying perpetrators from a group, which can lead to errors and miscarriages of justice.

  • Children may be more prone to false positive responses when identifying a perpetrator from a line-up that includes an innocent person.

Study Focus

• Pozzulo et al. explored social effects impacting child witnesses in line-ups, suggesting that children might make incorrect decisions due to:

  • Belief in needing to select a suspect (perception of 'non-response' as an invalid answer).

  • Viewing the questioner, often a figure of authority like a police officer, increasing compliance due to pressure (

  1. Compliance with requests

  2. Fear of consequences for not selecting).

Experiment Design

• Aims:

  • Assess how social and cognitive factors influence children as eyewitnesses.

• Predictions:

  1. Children will match adult accuracy in identifying cartoon faces in target-present line-ups.

  2. Children will be less accurate than adults in identifying human faces in target-present line-ups.

  3. Children will poorly reject cartoon faces in target-absent line-ups compared to adults.

  4. Children will poorly reject human faces in target-absent line-ups compared to adults.

Methodology

• Research Method and Design:

  • Laboratory experiment with three independent variables:

  • Age (children vs. adults).

  • Line-up type (identification: target-present vs. rejection: target-absent).

  • Level of cognitive demand (familiarity with targets: cartoons vs. humans).

  • Participants:

  • 59 children (ages 4-7, mean age 4.98) and 53 adults (ages 17-30, mean age 20.54).

  • Children from private schools, adults from a psychology participant pool.

  • Familiarity with cartoon characters (Dora the Explorer, Go, Diego, Go!) verified by guardians and adults.

Procedure

• Stimulus Preparation:

• Video Stimuli:

  • 6-second clips of two tasks: a female brushing hair and a male putting on a coat, shown with face close-ups.

• Photo Arrays:

  • Black and white images of close-cropped faces for human targets.

  • Cartoon faces represented through similar sources via three raters.

• Line-Up Presentation:

  • Target-present line-ups included the target and three foils.

  • Target-absent line-ups featured four foils.

  • All faces shown simultaneously, with randomized positions.

• Testing Children:

  • Conducted by female experimenters in a child-friendly environment.

  • Developed rapport through craft work before the experiment.

  • Responses recorded through pointing (for children) or writing (for adults).

Results

• Accuracy Rates:

  • Adults generally demonstrated higher accuracy compared to children across tasks.

  • Accuracy improved in cartoon identifications, with children performing similarly to adults in target-present cartoon conditions.

Conclusions

• Overall, findings supported the initial predictions. Children identified cartoon faces effectively, indicating any misidentification in target-absent conditions resulted from social pressures rather than cognitive errors.

• Implication: Social factors significantly influence children's decision-making in line-up settings, more so than cognitive factors.

Issues and Debates

• Practical Application:

  • Findings propose that minimizing social demands in line-up procedures can enhance the reliability of child testimony and improve judicial outcomes.

• Ecological Validity Concerns:

  • Conducting the study in a laboratory setting may lack the authentic gravity of a real line-up, possibly affecting emotional responses influencing decision-making.

• Ethical Considerations:

  • Ethical implications focus on the effects on participants, notably children potentially exposed to crime scenarios.

  • Researchers ensured informed consent, participant comfort, and monitored the psychological state to minimize risk in the research setting.

Strengths and Weaknesses

• Standardization:

  • Laboratory conditions provided controlled environments to enhance the reliability of responses.

• Quantitative Data:

  • Numeric data provided a means for statistical analysis across different conditions and participant groups, facilitating clear comparisons and conclusions.