Three significant factors make the formation of a friendship possible:
- Proximity – nearness or having a place or places to interact
- Repeated, unplanned interactions
- A setting that encourages people to confide in each other
Friendships end for many different reasons. Sometimes friends move away from each other and the relationship wanes due to the distance. Digital technology has however made geographic distance less of an obstacle to maintaining a friendship. Sometimes divorce causes an end to friendships, as people drop one or both of the divorcing people. For young people, friendships may end as a result of acceptance into new social groups.
Friendships may end by fading quietly away or may end suddenly. How and whether to talk about the end of a friendship is a matter of etiquette that depends on the circumstances.