Background. Higher education has been posited to protect against cognitive decline, either because
the rate of decline is slower in the more highly educated or the start of decline is delayed. Latent
growth models provide improved methodology to examine this issue.
Methods. The sample consisted of 887 participants aged 70–93 years in 1991 and followed up in
1994 and 1998. Latent growth models and standard regression techniques were used to examine the
rate of cognitive decline in four cognitive measures while controlling for health status and sex. A
delayed start model was examined by incorporating interaction effects in a regression model.
Results. Neither the latent growth models nor the regression techniques revealed a slower rate of
decline for the more highly educated. The proportion of the highly educated showing no change was
no larger than the proportion of the less well educated. There were no significant age by education
interaction effects, no chronologically later accelerations in the rate of change as a function of
education, and no differences in rate of decline between the first measurement interval and the
Conclusions. Education may not protect against cognitive decline although it is associated with
long-term individual differences in level of functioning. The discrepancy between our study and
others may be attributable to attrition effects, follow-up length, sample age, scaling artefacts and
negative publication bias. Most importantly, practice effects may favour the better educated and
hence account for the supposed protective effect in many longitudinal studies of cognitive change.