During the 20th century there has been a successive rise in mean intelligence (i.e. Flynn effect), where later born cohorts tend to outperform earlier born. Flynn effects have been reported regarding numerous cognitive abilities, and over age ranges from infants to 95 year olds. Less is known regarding possible birth cohort differences in rates of cognitive change in old age. We conducted a series of studies with the aim to investigate possible birth cohort differences in both level of cognitive performance and rate of change. We analyzed data from three representative, population based birth cohorts (born 1901-1902, 1906-07, and 1930) drawn from the Gerontological and Geriatric Population Studies in Gothenburg (H70), with measures on the same cognitive tests at the same ages (i.e., 70, 75 and 79 years). The results showed that later born cohorts outperformed earlier born on all cognitive measures (i.e., spatial ability, logical reasoning, verbal ability, perceptual-motor-speed, and long-term recognition memory), but also that later born cohorts declined at a faster rate on three cognitive outcomes (spatial ability, reasoning, and perceptual-motor-speed). Cohort differences in level of cognitive performance were expected and in line with previous studies, but our findings of cohort differences in rate of change are novel. A potential explanation for the cohort differences in rate of cognitive decline relates to differences in the average age of onset of the cognitive decline due to cohort differences in cognitive reserve. Another possible explanation relates to possible cohort differences in selective survival.