Definition
Psychological reactance is the motivational state, formalized by Jack Brehm in 1966, that arises when a person perceives that one of their freedoms is being threatened or eliminated. Reactance increases the felt importance of the threatened freedom and motivates behavior aimed at restoring it. Crucially, this motivation operates even when the person had no prior intention of exercising the freedom.
Cialdini draws on reactance theory in the Scarcity topic of Influence to explain why a thing becomes more desirable the moment it becomes hard to get. The desire is not produced by reassessment of the thing's value; it is produced by the discomfort of losing the option, and our drive to preserve options for their own sake.
Why it matters
How it works
Brehm's theory says we have a baseline expectation of which behaviors are available to us. When that expectation is contradicted — when a freedom we assumed was ours becomes blocked or limited — we experience reactance: an aversive arousal state that motivates restoration of the lost freedom. The restoration can take several forms: direct (exercise the threatened behavior anyway), indirect (find a substitute that asserts the same autonomy), or cognitive (downgrade the source of the threat, upgrade the value of the blocked option).
The reactance literature has documented the effect in domains as varied as advertising compliance, parental control of teenagers, censorship effects on persuasion (banning a speech raises both its audience and its persuasive power), and even pet behavior. Cialdini's Scarcity topic draws on this body of work to argue that most marketing scarcity is reactance-engineering rather than supply-signaling.
The defense is the before-test: imagine the option without the threat. If you wouldn't want the thing absent the deadline, the wanting is reactance, not preference.