Ageing and the Moses Illusion: Older adults fall for Moses but if asked directly, stick with Noah

Abstract

Many people respond “two” to the question “How many animals of each kind did Moses take on the ark?”, even though they know the reference should be to Noah. The Moses Illusion demonstrates a failure to apply stored knowledge (Erickson & Mattson, 1981). Of interest was whether older adults' robust knowledge bases would protect them from vulnerability to this illusion. Of secondary interest were any age differences in the memorial consequences of the illusion, and whether older adults' prior knowledge would protect them from later reproducing information from distorted questions (e.g., later saying that Moses took two animals of each kind on the ark). Surprisingly, older adults fell for the Moses Illusion more often than did younger adults. However, falling for the illusion did not affect older adults' later memory; they were less suggestible than young adults. Most importantly, older adults were more likely to recover from exposure to distorted questions and respond correctly. Explanations of these findings, drawing on theories of cognitive ageing, are discussed.

Keywords:

• Ageing
• Knowledge
• False memory

This research was supported by a Collaborative Activity award from the James S. McDonnell Foundation's 21st Century Science Initiative in Bridging Brain, Mind and Behavior (EJM). A National Science Foundation Graduate Research Fellowship supported the first author. We would like to thank the Duke Center for Aging for assistance with recruitment of older adult participants. We are also grateful to Meredith Mechanik for her assistance with data collection, and to Gabrielle Eagle, Blair Ganson, Lilly Stiff, Abby Ness, and Carrie Arndt for their help with data entry and participant recruitment.

This research was supported by a Collaborative Activity award from the James S. McDonnell Foundation's 21st Century Science Initiative in Bridging Brain, Mind and Behavior (EJM). A National Science Foundation Graduate Research Fellowship supported the first author. We would like to thank the Duke Center for Aging for assistance with recruitment of older adult participants. We are also grateful to Meredith Mechanik for her assistance with data collection, and to Gabrielle Eagle, Blair Ganson, Lilly Stiff, Abby Ness, and Carrie Arndt for their help with data entry and participant recruitment.

Notes

¹ As has been noted in prior work (Bottoms et al., 2010), the knowledge check is affected by the earlier experimental tasks. That is, exposure to distorted questions during the error detection phase reduces correct answers (for those specific questions) on the knowledge check, as compared to questions that tap information not encountered previously within the experiment (a baseline measure of knowledge). Key for present purposes is that older and younger adults were similarly affected by prior exposure to the distorted questions, answering about 7% fewer questions correctly on the knowledge check (OAs: from .84 to .77; YAs: from .74 to .66).