Study identifies basis for sense of trust in older people

Two new studies by NIA-funded researchers at UCLA have shown that older people are less adept than younger people at discerning visual clues of dishonesty in others. This may help to explain why many older people are more susceptible to financial fraud and other scams, the researchers found. Research results appeared online December 3, 2012, in the Proceedings of the National Academy of Sciences.

In the first study, investigators had 119 older adult (average age 68) and 24 younger adults (average age 23) look at 30 photographs of faces and rated them on how trustworthy and approachable they seemed. The faces were intentionally selected to look trustworthy, neutral, or untrustworthy.

Both groups reacted similarly to the trustworthy and neutral faces. But, younger adults reacted strongly to the untrustworthy faces, while the older adults did not. The older adults saw these faces as more trustworthy and more approachable than the younger adults.

In the second study, 23 older adults (average age 66) and 21 younger adults (average age 33) underwent functional magnetic resonance imaging brain scans while looking at the faces. The brains of the younger adults showed activity in the anterior insula region both when they were rating the faces and especially when viewing the untrustworthy faces. In contrast, the older adults displayed very little anterior insula activation during the imaging. The anterior insula is associated with “gut feelings,” which represent expected risk and predict risk-avoidance behaviors.

These studies are the first to show age differences in a characteristic pattern of brain activation in a "social" situation involving the assessment of another person's trustworthiness. Additional research is needed to determine whether the results are caused by age-related changes in the brain or if older adults are simply less motivated to look for social signals of untrustworthiness.

Reference: Castle, Elizabeth, et al. Neural and behavioral bases of age differences in perceptions of trust. Proceedings of the National Academy of Sciences. Published online December 3, 2012, www.pnas.org/cgi/doi/10.1073/pnas.1218518109.

Page last updated: December 7, 2012