Humans can mentally create and elaborately describe events, detailing not just the who, what, and where, but also the connections and intricacies of these elements. Propositional density (proportion of propositions/total words) can be leveraged to assess how elaborately the elements of memories are described. The present experiments used propositional density to investigate how age relates to the elaborateness of orally shared autobiographical event memories. Experiment 1 included 94 young adults (ages 18–26) and 91 older adults (ages 60–95) who completed two narrative tasks, including describing a recent autobiographical event. Experiment 2 was a preregistered experiment that included a larger sample: 110 young adults (ages 18–35) and 161 cognitively normal middle-aged/older adults (ages 50–83) who recalled multiple autobiographical event memories. Propositional density scores were calculated using Computerized Propositional Idea Density Rater (CPIDR 5.1). In Experiment 1’s autobiographical event memory task, propositional density was higher in older adults relative to young adults, p < .001, although this effect was driven by younger-old adults (ages 60–71), d = 0.80. Experiment 2, however, did not replicate the results of Experiment 1, instead finding that propositional density was higher in young adults relative to the oldest group of older adults in our sample (ages 69–83), p = .016, d = 0.41. In summary, the present experiments failed to find robust evidence that propositional density is higher in older relative to young adults within autobiographical event memory oral narratives. Rather, autobiographical event memory narrative elaborateness may be in a state of decline by advanced older age.
