Instruction Bias and Lineup Presentation Moderate the Effects of Administrator Knowledge on Eyewitness Identification

• Published in: Law and human behavior Vol. 33; no. 1; pp. 70 - 82
• Main Authors: Greathouse, Sarah M, Bull Kovera, Margaret
• Format: Journal Article
• Language: English
• Published: Boston Springer 01.02.2009; Springer US; American Psychological Law Society
• Subjects: Administrative law; Behavior; Behavioral Science and Psychology; Bias; Community and Environmental Psychology; Criminal investigations; Criminal Law; Criminal motive; Criminology and Criminal Justice; Evidence; Ex-convicts; Eyewitness identification; Face; Feedback; Female; Human; Human behavior; Humans; Hypotheses; Hypothesis testing; Identification; Identity; Knowledge; Knowledge Level; Law and Psychology; Male; Memory; Mental Recall; Original Article; Personality and Social Psychology; Police; Police lineups; Police Personnel; Psychological aspects; Psychology; Research biases; Statistical analysis; Studies; Suspicion; United States; Witnesses; Young Adult; United States; Lineups; Double-blind; Eyewitness identification; Memory
• ISSN: 0147-7307; 1573-661X
• DOI: 10.1007/s10979-008-9136-x

Pairs (N = 234) of witnesses and lineup administrators completed an identification task in which administrator knowledge, lineup presentation, instruction bias, and target presence were manipulated. Administrator knowledge had the greatest effect on identifications of the suspect for simultaneous photospreads paired with biased instructions, with single-blind administrations increasing identifications of the suspect. When biased instructions were given, single-blind administrations produced fewer foil identifications than double-blind administrations. Administrators exhibited a greater proportion of biasing behaviors during single-blind administrations than during double-blind administrations. The diagnosticity of identifications of the suspect in double-blind administrations was double their diagnosticity in single-blind administrations. These results suggest that when biasing factors are present to increase a witness's propensity to guess, single-blind administrator behavior influences witnesses to identify the suspect.