AS Psych: Pozzulo et al. (line-ups)
Psychology Being Investigated
1. Additional information given after the event seen by an eyewitness can produce false memories (piece of stored information an individual believes to be an accurate memory but is the consequence of later added and untrue information
2. Children may be eyewitnesses to crimes
– The legal system then has to rely on their eyewitness testimony (evidence provided by an individual who has seen/heard a crime being committed)
3. False positive response is giving an affirmative but incorrect answer to a question e.g. mistakenly picking out a person from a line-up when the real culprit is not there
– This study investigates why children would be more likely to make false positive response
Background
Pozzulo et al.
– Studied child witnesses and recognized that cognitive effects, like those cause by post-event information, can be responsible for errors in decision-making by children
Pozzulo and Lindsay (1998)
– Children are less likely than adults to say “I don’t know” in response to a question → even though they knew they could
– Children and adults produce comparable correct identification when shown target-present line-ups
– When targets are absent from the line-up, children were more likely than adults to identify an innocent person → this obstructs justice
This study focuses on the social effects on child witnesses
– It has been suggested that
1) Presentation of line-up suggests to the child that the presenter expects a decision to be made
2) The child is likely to view the adult who asks them a question as an authority figure, especially if it was the police → feel pressured to comply and make a choice as they don’t want to get in trouble
Aims
1. To investigate if the pattern in correct identification and false positive responding would remain when manipulating the familiarity of the target, using a cognitive and socially demanding line-up task.
2. To explore the effect of social vs. cognitive factors on children’s performance as eye witnesses.
Hypotheses
1. Children will be as good as adults at identifying cartoon faces in a target-present line-up
2. Children will be worse than adults at identifying human faces in a target-present line-up
3. Children will be worse than adults at rejecting human faces in a target-absent line-up
4. Children will be worse than adults at rejecting cartoon faces in a target-absent line-up
Method
Research method: Laboratory experiment
Research deign: Independent measures + Repeated measures
IV: age i.e. child/adult (for independent measures); line-up type i.e. target-present or target-absent + level of cognitive demand i.e. familiarity of target (for repeated)
DV: correct identification of face (target-present) OR empty silhouette (target-absent)
Sampling technique: Volunteer
Sample
Children
– 59 children
– Aged 4-7 years old (mean 4.98)
– 38 male, 21 female
– Recruited from pre-kindergarten/kindergarten classes (3 private schools in Eastern Ontario)
Adults
– 53 adults
– Aged 17-30 years
– 17 males, 36 females
– Recruited from Introductory Psychology Participant Pool (Eastern Ontario University)
Procedure
Video clip and line-up photograph preparation
1) Human face targets
– 2 Caucasian students
– 1 male, 1 female
– Filmed completing an everyday task in a 6 sec clip
– Male: putting on a coat + exiting home, female: brushing hair
2) Human face foils
– 2 human targets photographed in different outfits than in the video clips
– 4 “foil” photographs selected by 3 raters based on similarity of appearance to the 2 human targets
– Photoarrary was closely cropped + black and white
3) Cartoon targets
– 1 male, 1 female
– 6 sec clips: Dora the Explorer talking to the audience + Go, Diego, Go putting on a pair of gloves
4) Cartoon foils
– Selected from vast number of readily available cartoon images on the internet
– 4 “foils” chosen by 3 raters based on similarity in appearance to Dora and Diego
– Photoarrays were closely cropped to the target’s face
Young children’s procedure
– Parent/guardians gave written consent for their child to participate in the study + filled out a demographics sheet
– Demographics sheet: to ensure children are familiar with target cartoons
– After receiving the consent form and demographics sheet, 3 female experiments and 1 female facilitator arrived at the school
– They were introduced as a group from university doing a project on TV shows + computer games
– Made it clear to the children that they could change their mind about participating in the study and not get in trouble
– Did some arts and crafts with the children to make them comfortable
– Children (C) were monitored for fatigue, stress, and anxiety
– C told they would be watching some videos of people doing different things
– Told to pay attention as they would be asked questions and shown pictures
Results
Target-present line-ups
– Children had significantly higher correct identification rates of cartoon faces (0.99) than human faces (0.23)
– Adults had significantly higher correct identification rates of cartoon faces (0.95) than human faces (0.66)
– No difference in correct identification for familiar target
– Adults significantly better at identifying human targets from target-present line-up
Target-absent line-ups
– Children had significantly higher correct rejection rate for cartoon characters (0.74) compared to human faces (0.45)
– Adults had significantly higher correct rejection rate for cartoon characters (0.94) compared to human faces (0.70)
– Overall, adults’ performance was better than children’s performance for rejecting target-absent line-ups
Conclusion
1. Since children, like adults, were able to identify with 100% accuracy familiar (cartoon) targets, any error in target-absent line-ups are due to social demands to make a selection rather than cognitive factors e.g. faulty memory
2. Children are more likely than adults to choose an incorrect cartoon character than reject the line-up
Ethical Issues
✔ Informed consent – consent gained from parents/guardians + informed consent obtained from children in a child-friendly way
✔ Protection from harm – children’s comfort was ensured, fatigue, anxiety, and stress were monitored
✔ Right to withdraw – P were told they can withdraw at any time
Application to Daily Life
– In criminal cases where a child is the sole eyewitness, guidelines should be made to reduce tendency of false positives
– When presented with a line-up, children should be repeatedly reminded that the suspect may not be there, and they will not get in trouble for not being able to identify the suspect