Age effects and sample size in free listing

The literature in the psychology of aging shows cognitive declines among older adults in many abilities. This study addresses the question of whether informant age affects production in free listing. The study compares numbers of free-listed items across four quotidian domains by groups of older (n = 30) versus younger (n = 31) adults. Smaller samples of five, ten, fifteen, twenty, and twenty-five were also analyzed to assess age by sample size interaction at smaller sample sizes. Results show that at the level of the group and at every sample size, older adults produce more unique items than younger adults but that when idiosyncratic items (mentioned by only one person) are eliminated from the analysis, older and younger adults produce equivalent numbers of items. Finally, we varied the size of target sets (ten, fifteen, twenty) of most frequently cited items at thirty participants and examined the percentage of those items present for sample sizes of five, ten, fifteen, twenty, and twenty-five participants. For all set sizes and for both age groups, approximately 74-79% of items were present at n = 20 and 80-87% were present at n = 25. No effects were found for either different target set sizes or for age groups. These results suggest a modest advantage for older versus younger adults in free listing.