Neural and behavioral bases of age differences in perceptions of trust

Title: Neural and behavioral bases of age differences in perceptions of trust

Authors: Elizabeth Castle, Naomi Eisenberger, Teresa Seeman, Wesley Moons, Ian Boggero, Mark Grinblatt and Shelley Taylor; University of California, Los Angeles

Publication: Proceedings of the National Academy of Sciences of the United States of America (PNAS)

Year: 2012

Focus Area: Victim Profiling, Decision Making, Emotion/Motivation, Aging

Relevance: Understanding the biological basis of why older adults may be more vulnerable to financial fraud is helpful in order to develop more effective means of protecting them.

Summary: This study suggests that older adults’ vulnerability to fraud may result from their lack of response to visual cues of untrustworthiness.  In the first part of the study, older and younger adults rated people in photographs as “trustworthy,” “neutral,” or “untrustworthy” based on cues like insincere smiles, averted gazes, and postural difference.  Older adults and younger adults performed equally well when identifying people judged to be trustworthy or neutral, but older adults were much more likely to rate suspicious-looking people as approachable. In the second part of the study, participants underwent functional magnetic resonance imaging (fMRI) brain scans while evaluating the photographs. The researchers found that an area in the brain called the anterior insula, which is linked to disgust, displayed different patterns of activation in the two groups of participants. The younger adults showed anterior insula activation whenever they were making the ratings of the faces and especially when viewing the untrustworthy faces. In contrast, the older adults displayed very little anterior insula activation during evaluation of all faces.

Author Abstract: Older adults are disproportionately vulnerable to fraud, and federal agencies have speculated that excessive trust explains their greater vulnerability. Two studies, one behavioral and one using neuroimaging methodology, identified age differences in trust and their neural underpinnings. Older and younger adults rated faces high in trust cues similarly, but older adults perceived faces with cues to untrustworthiness to be significantly more trustworthy and approachable than younger adults. This age-related pattern was mirrored in neural activation to cues of trustworthiness. Whereas younger adults showed greater anterior insula activation to untrustworthy versus trustworthy faces, older adults showed muted activation of the anterior insula to untrustworthy faces. The insula has been shown to support interoceptive awareness that forms the basis of “gut feelings,” which represent expected risk and predict risk-avoidant behavior. Thus, a diminished “gut” response to cues of untrustworthiness may partially underlie older adults’ vulnerability to fraud.

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