Dateline: February, 2009, Issue 2
Borckardt and colleagues (2003) examined how jurors perceive eyewitnesses to a car accident when trivial details in one of the eyewitnesses' testimony are discredited.
Jurors were presented contradictory testimony from two eyewitnesses to a car accident. One witness' testimony included unnecessary and trivial details, while a second witness' testimony did not include these unnecessary, trivial details. The trivial details offered by the first witness were then discredited.
The credibility of the witness presenting the trivial details decreased after the trivial details were refuted. Interestingly, the first witness's loss was the second witness' gain: when the trivial details in the first witness' testimony were discredited, the credibility of the second witness increased despite no change in that testimony.
Discrediting even trivial details of a witness' testimony hurts a witness's credibility, and increases the credibility of witnesses who testify to opposing information.
Source Borckardt, J. J., Sprohge, E., & Nash, M. (2003). Effects of the inclusion and refutation of peripheral details on eyewitness credibility. Journal of Applied Social Psychology, 33, pp. 2187-2197.