Boys Will Be Boys; Cows Will Be Cows: Children’s Essentialist Reasoning About Gender Categories and Animal Species


  • This research was supported by National Institute of Child Health and Human Development Grant HD-36043 to Gelman. We thank the parents, teachers, and children at the following institutions in Ann Arbor, Michigan: University of Michigan Children’s Centers, the Jewish Community Center, St. Thomas Elementary School, and the YMCA. We also thank participating families and schools in Champaign-Urbana, Illinois, and surrounding areas: the University of Illinois Child Development Lab, the Learning Tree, Royal Elementary School, Schneider Elementary School, St. Matthew’s Elementary School, St. John’s School, Washington Elementary School, the Montessori School, the Don Moyers Boys and Girls Club, the University of Illinois Summer Science Program, the Thomas Paine Computer Camp, and the University of Illinois Summer Fitness Camp. We extend our appreciation to Cindy Andress, Mandy Davies, Galena Kline, Tracey Kramer, and Aisling O’Driscoll for their assistance with data collection and coding.

concerning this article should be addressed to Marianne Taylor, Department of Psychology, Pacific Lutheran University, Tacoma, WA 98447-0003. Electronic mail may be sent to


Two studies (N = 456) compared the development of concepts of animal species and human gender, using a switched-at-birth reasoning task. Younger children (5- and 6-year-olds) treated animal species and human gender as equivalent; they made similar levels of category-based inferences and endorsed similar explanations for development in these 2 domains. In contrast, 10-year-olds and adults treated gender and species concepts as distinct from one another. They viewed gender-linked behavioral properties as open to environmental influence and endorsed environment-based mechanisms to explain gender development. At all ages, children demonstrated differentiated reasoning about physical and behavioral properties, although this differentiation became more stable with age. The role of psychological essentialism in guiding conceptual development is discussed.