By Dr. Ken Broda-Bahm:
Here is a quick quiz. Who is more likely to guess or speculate about something they don't know, a novice or a trained expert? While we would like to think that the uninformed novice is more likely to make things up, the surprising answer is that it's actually the expert. A new study (Atir, Rosenzweig, & Dunning, 2015) finds that those with a high-level of self-perceived expertise are more likely to exaggerate their own knowledge and to claim to be familiar with concepts that are simply made-up by the researcher. Once someone thinks they're an expert in a given field, they are motivated to present themselves as knowledgeable, even to the point of saying that they know things they cannot possibly know. In other words, their own perceived expertise gives them enough confidence to feel that it's okay to B.S. a bit. The average nonexpert probably has a motivation to B.S. a bit when pressed as well. But it might be a little disconcerting to learn that the expert is more rather than less likely to give in to that temptation. Noting the irony, Jeremy Dean in Psyblog notes, "The more people think they know about a topic, the more likely they are to claim that totally made-up facts are true."
So what does that say about expert witnesses in trial and discovery? In that context, we are used to the perception, at least of a kind of "motivated dishonesty," where experts will lean toward what the paying client wants to hear. But we might be less familiar with the forms of unconscious dishonesty that can simply arise out of the arrogance of perceived expertise. If experts have a psychological bias that leads them to stray from their own expertise, that poses a practical problem for expert testimony. This post will take a look at the study on expert's tendency to make things up, and also share some thoughts on some of the mental reminders and commitments that expert witnesses should apply in order to avoid it.