Preschoolers and adults metonymically extend proper names to owned objects

Three preregistered experiments, conducted in 2021, investigated whether English-speaking American preschoolers (N = 120; 4-6 years; 54 females, predominantly White) and adults (N = 80; 18-52 years; 59 females, predominantly Asian) metonymically extend owners' names to owned objects-an extension not typically found in English. In Experiment 1, 5- and 6-year-olds and adults extended names to owned objects over duplicates (d = 0.34 in children; d = 1.13 in adults). In Experiment 2, 5- and 6-year-olds and adults extended names to owned over borrowed objects (d = 1.37 in children; d = 4.34 in adults). Experiment 3 replicated this finding with 4-year-olds (d = 0.43). Thus, English-speaking preschoolers can acquire semantic generalizations, even those not present in their language.