Conflict is said to escalate when one or both parties shift(s) to more extreme tactics – shouting instead of complaining softly, shooting instead of shouting, sending tanks instead of guerrillas. Escalation is the main reason why conflict has such a bad reputation. People are hurt and relationships are destroyed.

Escalation often develops through conflict spirals. Party A annoys party B, who retaliates, which provokes a more extreme tactic from A, and so on up the escalation ladder (Rubin et al. 1994; Pruitt and Kim 2003). Conflict spirals tend to take on a life of their own, in which the original issues may be all but forgotten.

Conflict often involves contentious behavior, in the sense of efforts to win, but this need not produce a conflict spiral. Conflict spirals occur when the parties engage in negative reciprocity, in which they respond to contentious behavior with more contentious behavior, fighting smoke with fire (Holmes and Murray 1996). Such spirals are avoided when the parties engage in accommodation and respond instead with yielding or problem solving (Rusbult et al. 1991).

Research on close interpersonal relationships shows that accommodation predominates in happy and committed relationships, while negative reciprocity predominates in distressed relationships (Sillars 1981; Rusbult et al. 1991; Bradbury and Fincham 1992). This means that in distressed relationships, even trivial conflicts tend to escalate, with each partner retaliating in response to the other's retaliatory behavior (Pruitt 1998).