Preschoolers' mutualistic conception of seeing is related to their knowledge of the pronoun "each other".

Previous research has shown that young children deny being able to see an agent whose eyes are covered. The current study explored this phenomenon further. In Experiment 1, 3-year-olds denied that they could "see," but affirmed that they could "look at," a doll whose eyes were covered--indicating that they demand mutuality for seeing another but not for looking at another. In Experiment 2, 3.5-year-olds drew the same distinction between "see" and "look at" when facing a doll or a human. A strong correlation between children's knowledge of the reciprocal pronoun "each other" and their adherence to the mutuality demand was found. The results are discussed with respect to children's bias for second personal encounters and children's relational concept of persons.