Attitude-Behavior-Context Model (ABC)

The attitude-behavior-context (ABC) framework explains environmentally significant behavior as the joint product of internal attitudes and external contextual conditions, and crucially as their interaction rather than their sum. Gregory Guagnano, Paul Stern, and Thomas Dietz proposed it in 1995 using a natural experiment on curbside recycling, and Stern incorporated it into his 2000 theory of environmentally significant behavior. The core claim is that attitudes most strongly drive behavior when external conditions are neutral — neither strongly enabling nor strongly blocking the action — and that when context is overwhelmingly favorable or prohibitive, behavior is determined by the context regardless of attitude. Providing recycling bins, for example, raises recycling so much that pro-environmental attitudes add little, while in the absence of any collection even strong attitudes cannot produce the behavior. The framework reconciles the often weak and inconsistent attitude-behavior correlations in environmental research by treating context as a moderator. It is typically estimated as an interaction regression and complements value-belief-norm theory.