The Effect of Distinctive Internal versus External Facial Features on Eyewitness Identification

Document Type


Degree Name

Doctor of Philosophy (Ph.D)


Psychology and Special Education

Date of Award

Summer 2021


Perpetrators of a crime can have distinctive features on the internal or external region of their face. The purpose of this study was to compare the effects of internal versus external distinctive features on eyewitness identification. I also compared these effects with two timed conditions of encoding, a 2 and 6 second condition, in order to investigate relatively short encoding times that mimic real world conditions. Finally, I tested two methods that police could utilize to deal with a distinctive feature: replicating it among all lineup members or removing it entirely. I found that an encoding time of 6 seconds resulted in better discriminability than 2 seconds and that a distinctive feature located on the internal region of the face reduced discriminability compared to the external region of their face. I found little difference between replication and removal of distinctive features across lineup members, although replication marginally improved discriminability over removal. Finally, I found a strong confidence-accuracy relationship across all conditions, suggesting that high eyewitness confidence in their lineup selection is indicative of accuracy in their choice of lineup member.


Curt Carlson

Subject Categories

Education | Educational Psychology