“The trouble with talking too fast is you may say something you haven’t thought of yet.” –Ann Landers
Regardless of the state in which they are testifying, New York, Texas, Illinois, Florida or Ohio to name a few, witnesses, even experts, are subjected to the same ohs and “ahs,” “ums” and “I don’t knows.” However, when an expert starts to falter, their perceived credibility becomes a source of juror doubt.
O’Barr, a social anthropologist, who wrote the book Linguistic Evidence wrote extensively about the comparison of different ways experts and witnesses spoke when testifying. Heading up a research team, O’Barr observed and taped over one hundred and fifty hours of trial activity over a ten week period. They studied various features of the language used by the persons who testified and how various language impacted the jurors’ beliefs.
In part, the study concluded that persons who hesitate; I…uh… think so, or who paused after being asked the opinion “hmm…yes” were less convincing than those who didn’t hesitate while testifying.
Now you might think that a person who takes time, who deliberately pauses before speaking is taking time to consider the question and all of its ramifications, and you would be correct. However, if a witness, especially an expert, uses too many pauses or is evasive and uses frequent pauses, then their lack of assertiveness is taken as insecurity.
O’Barr considers powerful speech to be convincing. Powerful speech is also necessary when you are an expert giving an opinion. If an expert says they “guess the answer is yes or no” they would be chided by the court and objected to by opposing counsel for not offering their opinion within a reasonable degree of certainty.