Dr. Katherine A. Dettwyler is an anthropology professor at the University of Delaware in Newark, Delaware. She is also a lecturer, author and breastfeeding advocate.
Dr. Dettwyler is best known for her work studying the duration of breastfeeding in humans as it relates to other mammals, primarily the nonhuman primates. According to her research, the natural age of weaning is 2½ to 7 years old as determined by weight gain, length of gestation, dental eruption, and other factors. She also studies the cultural context of breasts and breastfeeding in the United States, and is currently doing research on women in the US who nurse their children longer than 3 years.