A child must be your child, step child, adopted child, foster child, brother or sister, or a descendant of one of these (for example, a grandchild or nephew).
As a broad theory, symbolic interactionism appeared in the 20-s of XX century, in the Chicago school, its founder was an American sociologist George Mead. George Herbert Mead (1863-1931) is an American sociologist and social psychologist, who is considered a true founder of symbolic interactionism.
Symbolic interactionism is a sociological perspective which developed around the middle of the twentieth century and that continues to be influential in some areas of the discipline. It is particularly important in microsociology and social psychology.