In the Geneva Variability Study, the Stroop task was administered to children and young adults. Interference and facilitation effects were investigated by comparing mean reaction times (RTs) and applying ex-Gaussian distribution analysis. Our analyses were motivated by three goals: First, we aimed to replicate the results obtained with young adults by Spieler, Balota, and Faust (2000); second, we applied this method to children's data; third, the question of age-related differences in these inhibitory processes was investigated with the ex-Gaussian approach. In young adults, findings pertaining to the interference effect reported by Spieler et al. (2000) were replicated; in children, the interference effect was only manifested in the estimated Gaussian parameters (Mean RT, μ, σ); facilitation effects were only observed in children. The substantive meaning of the results and the advantages of ex-Gaussian analyses for describing RT distributions are discussed.