Beware the ‘expert’
If your mind is empty, it is always ready for anything; it is open to everything. In the beginner’s mind there are many possibilities; in the expert’s mind there are few. –Shunryu Suzuli
Critics of our jury system often decry the practice of removing people from juries who know too much about specifics relevant to a particular case. Recent years have seen much press coverage about physicians and even lawyers being allowed to sit on juries despite historical concerns that they could unduly influence other jurors. Researchers have indeed found that attitude change (and the willingness to allow attitudinal change) is related to a threshold level of relevant knowledge. At least a little bit of knowledge is a helpful thing.
A little knowledge or even an average amount of knowledge can still result in an individual open to changing their attitude. But having more than the average amount of knowledge (or simply perceiving yourself to have more knowledge—whether you really do or not) becomes detrimental to attitude change. Why? Because having (or believing that you have) specialized knowledge relevant to a particular situation/case results in biased processing—you fall back on what you believe to be true rather than listening to what the facts are and processing more carefully (Fives and Alexander 2001).
We saw this in a product liability case involving an automobile manufacturer. Prior to the case presentation, we measured the amount of knowledge participants in the focus group had about auto repairs and other mechanical areas. What we found was striking: the more people perceived themselves as having knowledge about cars and things mechanical, the more defense-oriented they tended to be. In deliberations they dismissed expert testimony about the frankly technical issues, relying instead in their ‘shade tree mechanic’ level of knowledge about how cars work. Those focus group members who did not have similar levels of self-perceived expertise were more frightened by what had happened and tended to be more plaintiff-oriented.
In this case, knowledge about a relevant case area resulted in a bad juror for the plaintiff case and thus, a good juror for the defense. Beware the self-professed expert with good verbal skills—unless it will work for your case. They will rely less on facts and more on their own beliefs.
Know when you want jurors who know something about your case and when you don’t.
Fives, H. and P. A. Alexander (2001). “Persuasion as a metaphor for teaching: A case in point.” Theory Into Practice 40(4): 243.