How To Mislead Using Nonverbal Communication – Study Shows That Eyewitness Testimony Is Influenced by Both Verbal And Non Verbal Cues
Christopher Philip
It is widely researched and accepted that verbal misinformation influences accuracy of eyewitness memory. Interviewers can lead witnesses to misremember details and even cause people to report false information.
Past research, however, has focused primarily on speech as the source of influence, but other studies have examined nonverbals such as doctored images (providing similar results). Other studies have even shown that certain gestures can serve to influence both adults and children.
As these findings are relatively new, researcher Daniel Gurney, University of Hertfordshire, UK devised a study to further test the validity of nonverbal influence on eyewitness testimony.
His study had witnesses review a short video of theft being committed at a bus stop. The video showed a girl waiting in the bus shelter where a man was seen entering and stealing the phone from a bag on the ground sitting beside her.
Subjects then underwent an interview consisting of five critical questions including the girl’s hairstyle, what item was stolen, where the man put the item, and what the bystanders were doing and what shape was present on a nearby poster.
Prior to the questions being asked, the interviewer deliberately used biased wording or hand gestures to present information to the participants. The information was presented either verbally, or nonverbally and either factually or misleading.
In the verbal condition the interview would say “the victim was using a phone” whereas in the nonverbal condition the critical information was presented through gesture while the speech was unbiased. For example, in the factual interview the interviewer would say “the victim was using an object”, “PHONE” gesture. When asked about the hairstyle of the women, they were asked “Did you see how the girl had her hair” combined with a “hair DOWN” gesture. The subjects were also mislead or presented factual gestures for the remaining questions with regard to where the phone was placed (jacket pocket versus jean pocket) and what the bystanders where doing (reading a book or reading a newspaper).
The results where quite dramatic; when the participants where presented with accurate nonverbal and verbal messages they were correct 75% of the time. However, when they were given non-accurate nonverbal and verbal messages this dropped to just 32% for verbal and 39% for nonverbal. The neutral control condition fell in between at 58%.
The researchers concluded that “gestures were as likely to prompt participants into reporting accurate, factual information and reporting inaccurate, misleading details about the scene as the same information presented overtly through speech.”
Importantly, while verbal prompts such as misleading statements or leading questions are often more overt and noticeable, nonverbal messages can often go unnoticed and therefore work on witnesses at a less conscious level. This can be troublesome for those who are not attuned to their effects, which as shown here, can be powerful and also destructive.
Additionally, while most interviewers have been trained to use neutral verbal language, few probably ever consider also using neutral nonverbal language.
The study clearly illustrates that the source of the message, both verbal and nonverbal, are key sources of influence over others and when used, can even prime or create virtual memories.
Image Credit: Tex Texin
Resources
Gurney, Daniel John. What’s Left Unsaid: How Nonverbal Influence Compares with Verbal Influence. Psychiatry, Psychology and Law. Dec 2019. DOI: 10.1080/13218719.2019.985624
http://dx.doi.org/10.1080/13218719.2019.985624