Exploring the generality of retest effects: commentary on "When does age-related cognitive decline begin?"

With respect to age differences in cognitive functioning, longitudinal and cross-sectional analyses have typically revealed differential patterns of results. Longitudinal comparisons show little or no age-related declines, whereas cross-sectional comparisons typically demonstrate poorer performance with increasing age. Salthouse presents evidence suggesting that longitudinal comparisons fail to detect age declines because the effects of prior test experience are not taken into account and that age-related declines in cognition begin in early adulthood. The present paper discusses some implications of these findings, such as their generalizability to other cognitive tasks, and highlights some additional findings in his paper that are worthy of discussion.