Adult age differences in forgetting sentences.

Age comparisons of performance-based measures of forgetting were carried out. In Exp. 1, 18- to 21-year-olds and 55- to 64-year-olds (n = 24) forgot at an equal rate when compared at 30 s and at 3, 6, and 24 hr after acquisition. In Exp. 2, 17- to 21-year-olds and 65- to 74-year-olds (n = 24) were compared at the same 4 retention intervals. Initial learning was equated for the 2 groups. There was evidence for an age difference in forgetting rate in cued recall when a minimal learning level was required. In Exp. 3, 440 men and women 17 to 74 years old were assigned to a retention interval from 10 min to 7 hr. Age was related to 4 performance-based measures of forgetting rate. Although the age differences were small, they imply 2 decremental processes: 1 before 10 min, possibly a result of incomplete consolidation, and a later 1 that is continuously and cumulatively operative thereafter. Evidence relating initial level to forgetting rate is presented.