This work investigates cerebral cortical thinning as a function of age, and how this relationship varies between four healthy subject databases, with a consolidated 1,382 subjects. Cortical thickness measurements of each subject were computed for 68 regions. Linear regression was used to determine the thinning rate for each region in each database as well as for the consolidated database. ANCOVA tests were run to test the effect of database. Correlation matrices were used to test the intra-relationship of locations between databases. Statistically significant correlations were found with age and differences were found between databases in all regions.