Despite long experience with the ways of the world, older people are especially vulnerable to fraud.
According to the US Federal Trade Commission (FTC), up to 80 per cent of scam victims are over 65.
One explanation may lie in a brain region that serves as a built-in crook detector.
Called the anterior insula, this structure - which fires up in response to the face of an unsavoury character - is less active in older people, possibly making them less cagey than younger folks, a new study finds.
Both FTC and the Federal Bureau of Investigation have found that older people are easy marks due in part to their tendency to accentuate the positive.
According to social neuroscientist Shelley Taylor of the University of California, Los Angeles, research backs up the idea that older people can put a positive spin on things - emotionally charged pictures, for example, and playing virtual games in which they risk the loss of money.
"Older people are good at regulating their emotions, seeing things in a positive light, and not overreacting to everyday problems," she said. But this trait may make them less wary.
To see if older people really are less able to spot a shyster, Taylor and colleagues showed photos of faces considered trustworthy, neutral, or untrustworthy to a group of 119 older adults (ages 55 to 84) and 24 younger adults (ages 20 to 42).
Signs of untrustworthiness include averted eyes; an insincere smile that doesn't reach the eyes; a smug, smirky mouth; and a backward tilt to the head.
The participants were asked to rate each face on a scale from -3 (very untrustworthy) to 3 (very trustworthy).
In the study, appearing online today in the Proceedings of the National Academy of Sciences, the "untrustworthy" faces were perceived as significantly more trustworthy by the older subjects than by the younger ones.
The researchers then performed the same test on a different set of volunteers, this time imaging their brains during the process, to look for differences in brain activity between the age groups.
In the younger subjects, when asked to judge whether the faces were trustworthy, the anterior insula became active; the activity increased at the sight of an untrustworthy face.
The older people, however, showed little or no activation.
Taylor explains that the insula's job is to collect information not about others, but about one's own body - sensing feelings, including "gut instincts" - and present that information to the rest of the brain.
"It's a warning bell that doesn't seem to work as well in older people."
By habitually seeing the world in a positive light, older people may be overriding this warning signal, she said.
"It looks like the brain is conspiring with what older people do naturally."
Whether the insula activates in response to non-facial cues, such as telephone scams (a particular problem for older people), remains unclear, said Taylor, since the study was limited to faces.
The new study is the first to show a characteristic pattern of brain activation in a "social" situation involving the assessment of another person's trustworthiness, said psychologist Lisbeth Nielsen of the National Institute on Aging (NIA) in Bethesda, Maryland. (Though NIA funded the project, Nielsen was not involved in the study.)
A question to be addressed in future research, she said, was whether decreased activity in the insula is the cause or the effect of older peoples' more positive outlook.
"It may be that older people engage with the world in a certain way and this is reflected in the brain activity."
If so, she added, older people could work on becoming more cautious. For example, they could be taught to look out for the facial signs of untrustworthiness.
"Just because the insula isn't being activated doesn't mean it can't be."
- SCIENCE NOW
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