Exaggerated claims and low levels of reproducibility are commonplace in psychology and cognitive neuroscience, due to an incentive structure that demands “newsworthy” results. My overall argument here is that in addition to methodological reform, greater modesty is required across all levels - from individual researchers to the systems that govern science (e.g., editors, reviewers, grant panels, hiring committees) - to redirect expectations regarding what psychological and brain science can effectively deliver. Empirical work and the reform agenda should pivot away from making big claims on narrow evidence bases or single tools and focus on the limitations of our individual efforts, as well as how we can work together to build ways of thinking that enable integration and synthesis across multiple modalities and levels of description. I outline why modesty matters for science including the reform agenda, provide some practical steps that we can take to embrace modesty, rebut common misconceptions of what modesty means for science, and present some limitations of the approach. Ultimately, by presenting a more sober view of our capacities and achievements, whilst placing work within a wider context that respects the complexity of the human brain, we will bolster the fidelity of scientific inference and thus help in a small way to generate a firmer footing upon which to build a cumulative science.