Department of Psychology researchers Ted Ruffman, Janice Murray and Jamin Halberstadt compared young and older adults’ skills at deception as judged by listeners within and outside their age group. Dr Murray presented the findings today at the Association of Psychological Science’s annual convention in Washington, D.C.
The study involved 60 participants being shown video clips of 20 people expressing their actual or false views on topical issues such as factory farming and stem cell use in humans. Ten of the speakers were aged 30 or under and 10 were 60 or over. Two clips of each speaker were shown; one in which they were lying, and the other being truthful.
The 60 listeners, who consisted of two equal-sized groups with average ages of 21 and 71, were asked to determine if the person in each clip was being truthful or lying. They also underwent tests that required judgments of emotional expression and age in faces.
Associate Professor Halberstadt says the results of the lie detection test showed that both young and older listeners found it easier to differentiate truths and lies when the speaker was an older adult compared to a young adult.
“It could be that older people are less convincing liars because the kinds of cognitive abilities required for successful deceit are also those that tend to deteriorate with age,” he says.
Lying places demands on memory and planning ability (e.g., formulating a plausible argument, keeping story facts straight) and on social understanding (e.g., judging whether a particular argument will convince a listener, as well as keeping track of a listener’s response as the lie unfolds to potentially alter the argument).
“In our study, we also found that older participants in the lie detection test were not as good as their younger counterparts at differentiating between lies and truths.”
Further analysis showed that older people’s scores in the emotion recognition test strongly predicted how well they would do in the lie detection task.
“As with our recent findings on older people’s worse abilities in detecting social gaffes, and also older men’s tendency to talk for too long and go off topic when talking, age-related decline in emotion perception was again linked to a poorer performance in the phenomenon being studied.”
The research team also examined an idea proposed by previous researchers that recognising brief flashes of negative facial emotions such as guilt, fear or disgust, known as “micro-expressions”, plays a key role in detecting lies.
To do this, in the emotion recognition test the team showed participants images of faces displaying one of six different types of emotion, varying the duration of the images on the computer screen. The three durations used were 1/20th of a second, ¼ of a second, or until the participant assigned an emotion to the face.
“While emotion recognition ability explained the difference in lie detection between young and older adults, there was no particular advantage associated with correctly identifying facial emotions displayed for the shorter times. These results suggest that recognising micro-expressions is perhaps not necessarily key to detecting deceitfulness after all,” Associate Professor Halberstadt says.
He says that people who are lying could well be sending out detectable signals with some emotional content, but these may or may not solely revolve around facial expressions, and do not necessarily leak out only briefly.
“Emotion recognition also involves auditory and body-language aspects, so the giveaway signals might additionally, or instead, be heard in the voice or seen in emotions expressed through the body. We still don’t know what exactly allows listeners to correctly detect lies, although we know that people can differentiate lies and truth at a rate above chance level – though they are far from perfect.”
Associate Professor Halberstadt says that it would be interesting to study whether older adults’ difficulties telling and detecting lies affects their susceptibility to fraud schemes and their general social well-being.
“As well as problems arising from being more easily deceived, a reduced ability to tell white lies that spare others’ feelings may impair their relationships, for example.”
The team’s findings are also being published in the US journal Psychology and Aging. Tina Vater, who is now with the University’s Injury Prevention Research Unit, was also a study co-author.
For more information, contact
Associate Professor Jamin Halberstadt
Mob 027 688 9899
Email [email protected]
Dr Janice Murray
Mob 612 638 8117