The I Model: a metatheoretical framework for understanding aggression.

The I Model is a general-purpose metatheory. It posits that three orthogonal processes influence the likelihood and intensity of a given behavior, including aggressive behavior. Instigation encompasses immediate environmental stimuli (e.g., provocation) that normatively afford an aggressive response. Impellance encompasses situational or dispositional qualities (e.g., trait aggressiveness) that influence how strongly the instigator produces a proclivity to enact that response. Inhibition encompasses situational or dispositional qualities (e.g., alcohol intoxication) that influence how strongly the proclivity is overridden rather than manifesting in aggressive behavior. Extant evidence supports Perfect Storm Theory-a theoretical perspective derived from the I Model-which posits that aggression is especially likely, and especially intense, to the extent that instigation and impellance are strong and inhibition is weak.