64 subjects, aged 5, 7, 9, and adult, participated in a visual discrimination task. Standard photographs of adult models were accompanied by comparison photographs of either the same person as in the standard or a different person with systematic variation of both facial expression and attire. Subjects were asked if the person pictured in the standard was the same or different than the person in the comparison photograph. Subjects made fewer overgeneralization errors than overdiscrimination errors. The number of overdiscrimination errors varied with the age and sex of the subject and the pose and sex of the model. The number of overgeneralization errors varied with the age of the subject and the degree of similarity between the model pairs.