Expanded the Simple ABCX theory by explaining the family adaptation and response to stressful events over time, from precrisis, through crisis and postcrisis. After the initial stressful encounter, changes in family states are driven by the pileup of stressors (aA) that accumulate according to hardships and consequences; existing and new resources (bB) drew upon recovery; expanded perception (cC), the coping strategies and understanding of the relationship between stressors and resources; and adaptation (xX), the resulted stationary state of functioning acquired after transition through crisis.
Posited by Hamilton McCubin and Joan Patterson (1983)