Abstract
Financial fraud through false advertising has become increasingly prevalent among both younger and older adults, yet the neuropsychological mechanisms underlying real-time, face-to-face deceptive sales are unclear. In addition, the effects of guilt appeal as a marketing strategy, across age groups, remain unexplored. We used functional near-infrared spectroscopy hyperscanning to examine purchase decisions and neural mechanisms by age group and sales approach (guilt vs. control) in a face-to-face sale mimicking real-life scenarios. Older adults had higher purchase intentions for products promoted by false advertising across sales approaches compared to younger adults. However, younger adults were more likely to be influenced by guilt appeal. The neural results aligned with the behavioral finding that younger adults' intra-brain functional connectivity and inter-brain synchronization values were greater in the guilt condition than in the control, whereas no difference between conditions was found for older adults. Using inter-subject representational similarity analyses, we identified distinct neuropsychological mechanisms between two age groups. Younger adults' frontopolar activity was associated with the advertising credibility, whereas older adults' frontopolar activity was associated with the trustworthiness of the salesperson during deceptive sales. These findings provide insights into age-specific vulnerabilities and may inform tailored consumer fraud prevention strategies targeting younger and older adults separately.