The term kinship usage means the rules governing the behavior with different kins. It provides guidelines for interaction among different persons in a social group. It defines proper and acceptable role relationships. Thus, it acts as regulator in social life. According to avoidance in kinship usage, two kins of opposite sex should remain away from each other, i.e., they should avoid each other.
They should avoid even seeing the face of each other. Thus, a father-in-law is supposed to avoid a daughter-in-law. Similarly, a mother-in-law avoids a son-in-law. In some societies, avoidance is also maintaineddf between brothers and sisters. The purdah system of the Indian society illustrates the usage of avoidance. Radcliffe Brown and G.P. Murdock have given functionalist explanation for avoidance. According to them, the purpose of avoidance usage is to forestall further or even more serious trouble between the kins.