News in Science

Older brains more vulnerable to fraud

Too trusting? An ancient warning system in the brain fails to fire in older people making them especially vulnerable to fraud, finds a US study.

The brain region called the anterior insula is activated when young adults look at pictures of untrustworthy faces, but fails to respond when older adults see the pictures, reports Professor Shelley Taylor of the University of California, Los Angeles.

Older adults asked to rate pictures of faces as trustworthy, neutral or untrustworthy, tend not to spot untrustworthy faces, Taylor and her team write in the Proceedings of the National Academy of Sciences.

The findings could go some way to explaining why elderly people in the US lose $2.9 billion per year in financial scams and swindles, says Taylor.

The study, comparing 119 older people from a retirement village aged between 55-84 with 24 university students and staff aged 20-42, found the older adults were not more trusting across the board. The two groups gave equal ratings when looking at trustworthy or neutral faces.

It was when looking at untrustworthy faces that the older people slipped up - consistently failing to spot the warning signs that stood out to younger people.

Do I trust you?

Taylor says there are many factors that younger brains pick up subconsciously when looking at a face that warns the person may be a fraudster.

An averted or shifty gaze, lack of a smile, or an insincere smile involving only the mouth with no eye crinkling, are cues of untrustworthiness, she says. Male faces are less trusted than female, she adds, while a beard or moustache makes matters even worse.

The researchers went on to look at the brain activity of 23 older people and 21 young adults as they were shown the face pictures while inside an fMRI brain scanning machine.

The left anterior insula was very active when the younger people looked at the untrustworthy faces, but didn't seem to be firing in the older people.

The home of gut feelings

The anterior insula is involved in 'gut feelings' says Taylor.

"It's a very very old part of the brain - reptiles have it - so it's not a verbal part of the brain. You get a subtle 'uh oh' sense from the insula. It's saying 'something's not quite right here'. It's a warning signal."

The region is also involved in the uncomfortable bodily feelings we have when under stress or threat and feeling disgust, she says.

Taylor says the findings fit in with other researchers' work showing that older people tend to "make their lives more positive. They avoid negative situations and they don't react so much to minor stressors."

"This is generally a good thing for older adults. It's nice to have your life on a positive emotional keel. But the problem is you're not getting the cues to untrustworthiness that you should be getting."

Taylor feels elderly people should cut off marketing of financial investments at the source. "Just hang up", she says.

"This is a very interesting set of results," says Professor Eddie Harmon-Jones of University of New South Wales. "It's important that they've not only collected neural evidence, but also have strong behavioural evidence consistent with the results."

Harmon-Jones, who was not involved in the study, says the psychological changes we experience as we age are "both good and bad".

"As we age we may become more wise, better able to feel positive emotions and better recover from negative emotions and these are all beneficial. But ageing also has some drawbacks - making us more likely to be hoodwinked."