James Asher developed the total physical response (TPR) method as a result of his observation of the language development of young children. Asher saw that most of the interactions that young children experience with parents or other adults combine both verbal and physical aspects. The child responds physically to the speech of the parent, and the parent reinforces the child's responses through further speech. This creates a positive feedback loop between the parent's speech and the child's actions. Asher also observed that young children typically spend a long time listening to language before ever attempting to speak, and that they can understand and react to utterances that are much more complex than those they can produce themselves.