Expert Witness Training History and Professional Experience Exert Separable Impacts on Expert Credibility Perceptions

ABSTRACT

This study experimentally tested jurors’ claims that their expert credibility perceptions are independently influenced by expert training and experience, with the latter exerting greater influence. To our knowledge, only the combined impact of these variables had been previously examined. Mock jurors (N = 553) read a trial summary containing testimony from a forensic expert with high or low training and with high or low experience. They then rendered verdicts and rated the expert’s credibility. Results mainly showed that expert training and experience independently influenced expert credibility, although the latter exerted only a slightly greater impact. Practical implications and future directions are discussed.

KEYWORDS:

• Expert testimony
• expert knowledge
• expert credibility
• mock jurors
• forensic psychology
• psychology and law

Disclosure statement

No potential conflict of interest was reported by the authors.

Data availability statement

All data pertaining to this article are available via this OSF link: https://osf.io/63ugp/?view_only=b82306ce8208461b9488275e163dbabf.

Notes

¹ We collected well above our target of N = 485 because data collection occurred over the course of two full semesters. Therefore, we did not monitor the data mid-semester to stop at exactly N = 485.

² To increase power, only mock jurors who self-identified as male or female (n = 542) were included in analyses containing mock juror gender as a variable.

³ We also ran a binary logistic regression model with an independent variable possessing five different levels, one for each of our five conditions, and verdict as the dependent variable. The main effect of this variable was not significant, p = .830, suggesting the control condition did not significantly differ from any one specific experimental condition in terms of verdict decisions.