Not All Fair Lineups Are Created Equally: The Effect of Lineup Composition on Eyewitness Identification

Document Type


Degree Name

Master of Science (MS)


Psychology and Special Education

Date of Award

Fall 2018


Eyewitness identification (ID) is influenced by lineup fairness, with biased lineups harming empirical discriminability (the ability of a group of eyewitnesses to discriminate between guilty and innocent suspects). Researchers have developed lineup fairness measures as well as have tested fair versus biased lineups, but there is much more to be learned about various degrees of fairness. In two experiments, I created faces and lineups with a computer-generated face software. Doing so allowed for the precise operationalization and control of lineup fairness. I utilized a multiple-block face recognition paradigm in both experiments to investigate the effect of lineup fairness on eyewitness ID. Participants took part in several trials, each of which tested their memory for a single face using a lineup varying in fairness (e.g., homogeneity of certain facial features). In Experiment 1, witnesses who viewed the lineups of highest fairness performed better than those who viewed lineups that were slightly less fair, but unexpectedly not better than those who viewed lineups of even lower fairness. In Experiment 2, witnesses who were presented with a lineup performed worse than those who were presented with a showup (a single-person ID procedure), in contrast to the literature. These results indicate a complex relationship between fairness and empirical discriminability, such that a higher level of lineup fairness does not necessarily make eyewitnesses make better decisions.


Curt A. Carlson

Subject Categories

Psychology | Social and Behavioral Sciences