Our results provide evidence of the fundamental role played by stellar mass in regulating the active phase of star-formation at any redshift spanned by our investigation. Our analysis supports the scenario where star-formation activity proceeds from high- to low-mass systems, with massive galaxies having formed most of their stars at an early epoch, while low-mass systems have been forming their stellar component over the whole redshift interval. A clear link exists between younger (older) stellar populations and low- (high-) mass galaxies over the whole cosmic epoch spanned by our sample, extending similar results obtained in the local Universe. The fraction of massive galaxies with old stellar population is increasing with look-back time to the extent that the peak of massive galaxies with old underline stellar population becomes extremely under-populated at redshift larger than z ~ 1.