Sixty-four children aged 3-7 (M = 5.58, SD = 1.28) were presented with a Conservation of Liquid task assessing their Cognitive Development (specifically Concrete Operational Skills), a false-belief task to measure possession of Belief-Desire Theory of Mind, and a task measuring the ability to acknowledge multiple possibilities. The ability to elaborate on potential negative outcomes was assessed using a Worry Elaboration task. Mediation analysis revealed that all three variables significantly mediated the relationship between Age and Worry Elaboration. A multiple mediation model is presented in which Concrete Operational Skills, Belief-Desire Theory of Mind and Multiple Possibilities understanding mediate the relationship between Age and Worry Elaboration. (Published Abstract)