This article provides an overview of current findings on Theory of Mind (ToM) in human children and adults and highlights the relationship between task specifications and their outcome in socio-cognitive research. ToM, the capacity to reason about and infer others’ mental states, develops progressively throughout childhood—the exact time course is still a matter of debate. Neuroimaging studies indicate the involvement of a widespread neuronal network during mentalizing, suggesting that ToM is a multifaceted process. Accordingly, the tasks and trainings that currently exist to investigate and enhance ToM are heterogeneous, and the outcomes largely depend on the paradigm that was used. We argue for the implementation of multiple-task batteries in the assessment of socio-cognitive abilities. Decisions for a particular paradigm need to be carefully considered and justified. We want to emphasize the importance of targeted research on the relationship between task specifications and outcomes.