AbstractJudgments concerning personal identity were studied in children and adolescents. Each subject was asked to imagine entering a hypothetical machine which simultaneously produced two persons, with each person receiving one of four sets of the subject's characteristics: physical, active, social, or psychological. Subjects were asked to judge which of the resulting persons was most nearly identical with the self. Results from the first study with middle‐class Americans demonstrated that the social characteristics are most frequently chosen by young adolescents. With age, the physical characteristics were less frequently selected and the psychological characteristics were more often selected. In Study 2, middle‐class American children between the ages of 6 to 7 judged the psychological characteristics of self most important in preserving identity, even though their self‐concepts as elicited by other methods appeared physicalistic. The results are discussed in terms of their implications for accounts of self‐concept deve