Shunning can be the act of social rejection, or emotional distance. In a religious context, shunning is a formal decision by a denomination or a congregation to cease interaction with an individual or a group, and follows a particular set of rules. It differs from, but may be associated with, excommunication. The social rejection occurs when a person or group deliberately avoids association with, and habitually keeps away from an individual or group. This can be a formal decision by a group, or a less formal group action which will spread to all members of the group as a form of solidarity. Shunning can sometimes also be used by an individual to express discontent with an action of their family. Sometimes shunning leads to shunning in itself. An example would be a son using shunning to stop their mother from shunning someone.
Shunning is a sanction against association, often associated with religious groups and other tightly knit organizations and communities. Targets of shunning can include persons who have been labeled as apostates, whistleblowers, dissidents, strikebreakers, or anyone the group perceives as a threat or source of conflict. Shunning can also be the result of the love life of a person. This often results because of marriage/dating outside of their religion/class. In these cases it's most often the direct family of the couple which shun the couple because of discontent with the marriage (interfaith marriages). This can be motivated by fear of the reaction of their community or because of personal beliefs.