Three-year-old children's reasoning about possibilities.

Recent studies in cognitive development suggest that preschoolers may not be able to represent alternative possibilities, and therefore may lack modal concepts such as possible, impossible, and necessary (Leahy & Carey, 2020). We present two experiments adapted from previous probability studies but have a similar logical structure as those used in the previous modal reasoning tasks (Leahy, 2023; Leahy, Huemer, Steele, Alderete, & Carey, 2022; Mody & Carey, 2016). Three-year-old children have to choose between a gumball machine that must produce the desired gumball color and a gumball machine that merely might produce the desired gumball color. Results provide preliminary evidence that three-year-old children can represent multiple incompatible possibilities, and therefore have modal concepts. Implications for the study of modal cognition, and how possibility and probability may be related are discussed.