Cognitive skills are commonly assumed to begin deteriorating from the age of 30, which could pose a significant challenge for rapidly
ageing populations. But this assumption relies largely on cross-sectional data that cannot distinguish between ageing patterns and
cohort differences. Using German longitudinal data, this column finds that skills, on average, increase markedly into one’s 40s before
decreasing slightly in literacy and more severely in numeracy. In addition, skills decline at older ages only for those with below-average
skill usage, outlining a clear policy pathway for avoiding skill declines.