Inter- and intra-individual variation in immediate free recall: an examination of serial position functions and recall initiation strategies

Serial position functions in immediate free recall have been historically noted for their bowed shape, where items presented at the beginning (primacy) and end (recency) of a list are better remembered than those presented in the middle. While extensive work has examined these effects, researchers typically ignore the systematic differences among individuals that likely contribute, but are lost when using an aggregate function. In the current study, inter- and intra-individual differences in serial position functions and differences in recall strategies were examined. Participants performed a free recall task on multiple lists. Three groups of participants were derived based on the relative profiles in their serial position functions. These groups differed in the extent that they output mainly primacy items, recency items, or both primacy and recency items. Performance on immediate free recall and on cognitive ability tasks was compared between these three groups. Systematic inter- and intra-individual variation in recall strategies led to differential profiles of performance in immediate free recall, which was also related to the additional cognitive ability measures. Performance on a task can be due to the utilisation of a variety of control processes that emphasise various components of that task over other components.