In the fMRI literature, most authors reported solely the significance of their findings which hampered the critical interpretation of the found results and power analyses for subsequent studies. To reveal the effect size and overlap between individual subject activation maps, we reanalyzed data from multiple fMRI studies. For each of the 44 contrasts tested, our study revealed fairly strong effect sizes and reasonable overlap between the individual results. However, the overlap between the individual results and the results of the corresponding group analysis was rather poor. This observation supports the call that reporting significance solely, is not enough.