The damaging effect of confirming feedback on the relation between eyewitness certainty and identification accuracy.

The authors investigated eyewitnesses' retrospective certainty (see G. L. Wells & A. L. Bradfield, 1999). The authors hypothesized that external influence from the lineup administrator would damage the certainty-accuracy relation by inflating the retrospective certainty of inaccurate eyewitnesses more than that of accurate eyewitnesses (N=245). Two variables were manipulated: eyewitness accuracy (through the presence or absence of the culprit in the lineup) and feedback (confirming vs control). Confirming feedback inflated retrospective certainty more for inaccurate eyewitnesses than for accurate eyewitnesses, significantly reducing the certainty-accuracy relation (from r=.58 in the control condition to r=.37 in the confirming feedback condition). Double-blind testing is recommended for lineups to prevent these external influences on eyewitnesses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)