Why young children think actions aren't swayed by sunk costs: Testing two accounts.

Adults think that sunk costs are relevant to predicting choices, but young children do not. In this article, we tested between two accounts for why children do not make sunk cost predictions. One account holds that children conceive of sunk costs in a fundamentally different way than adults. The other account denies this but holds that children do not reason about sunk costs spontaneously. We tested between these accounts in three experiments on 4- to 7-year-olds (N = 484). Children saw sunk cost scenarios where an agent collected objects that were easy or difficult to obtain but could only keep one. Before predicting the agent's choice, children were prompted to think about some aspect of the situation theorized to underlie sunk cost predictions in adults (effort, waste, emotion) or instead were asked a control question. The findings supported both accounts. In line with the spontaneity account, children aged 6 and older made sunk cost predictions when prompted to think about effort (all experiments), the agent's emotions (Experiment 1), and one form of waste (Experiment 3). However, in line with the account positing discontinuity between children and adults, prompting did not bring younger children to make sunk cost predictions, and even among older children, predictions were not at ceiling. This suggests that sunk costs are not fundamental to conceptions of choice. The developmental shift we observed likely reflects broadening in the factors that children see as relevant for choices around objects. We discuss potential drivers of this shift, including firsthand experience with costs and enculturation. (PsycInfo Database Record (c) 2026 APA, all rights reserved).