COVID-19 misinformation proliferating online has led to adverse health and societal consequences. Older adults are a particularly vulnerable population due to increased risk for both COVID-19 related complications and susceptibility to, as well as sharing of, misinformation on social networking sites. The present study aimed to: 1) investigate differences in COVID-19 headline accuracy discernment and online sharing of COVID-19 misinformation in older and younger adults; and 2) examine individual differences in global cognition, health literacy and verbal IQ in online sharing of COVID-19 misinformation.

Fifty-two younger (age 18 to 35 years) and fifty older adults (age 50 and older) completed a telephone neurocognitive battery, health literacy and numeracy measures and self-report questionnaires. Participants also completed a social media headline-sharing experiment (Pennycook et al.,2020) in which they were presented true and false COVID-19 headlines and asked to indicate: 1) the likelihood that they would share the story on social media; and 2) the factual accuracy of the story.

A repeated measures multivariate analysis of variance controlling for gender and race/ethnicity showed no effects of age (p=.099), but a significant interaction between actual COVID-19 headline accuracy and likelihood of sharing (p<.001), such that accuracy is more strongly related to sharing false headlines (r=-.64) versus true headlines (r=-.43). Moreover, higher likelihood of sharing false COVID-19 headlines was associated with lower verbal IQ and numeracy skills in older adults (rs=-.51--.40; ps<.01) and with lower verbal IQ, numeracy, and global cognition in younger adults (rs=-.66--.60; ps<.01).

Findings indicate that headline accuracy judgements are an important predictor of sharing COVID-19 misinformation in both older and younger adults. Further, individual differences in cognition, IQ, and numeracy may predict the likelihood of misinformation sharing in younger adults, while IQ and numeracy skills may act as important antecedents of misinformation sharing in older adults. Future work might leverage modern, neuropsychologically-based psychoeducation approaches to improving health and science literacy related to COVID-19.