Understanding possibility through action: Young children’s modal reasoning in agentive contexts

When does the ability to reason about alternative possibilities emerge during cognitive development? This has been a matter of considerable dispute. Conservative accounts assume that modal reasoning emerges relatively late, not before age 4 (Carey et al., 2020). Evidence for these accounts comes from tasks where children fail to take into account mutually incompatible possibilities. However, it is unclear whether these failures truly reflect competence deficits, or rather performance limitations. One recent suggestion is that modal reasoning tasks are mastered earlier if children need to deliberate about which outcome they could bring about rather than respond to events beyond their control (Phillips & Kratzer, 2024). The present studies tested this suggestion. In Study 1, 3- and 4-year-old children received tasks in which they could exert agentive control over the realization of the outcome: they chose between performing an action that must lead to a reward and an action that might lead to a reward. Study 2 examined whether children's performance is influenced by superficial task factors, by the type of agentive modality (acting oneself vs. directing someone else's action), and by the type of uncertainty (reasoning about what could be the case in the future vs. what could be the case at present, but is (still) unknown). Results indicate that even 3-year-olds perform competently in some tasks where they control the outcome. Altogether, our findings suggest that modal reasoning competences can be masked by performance factors under certain circumstances.