The core of the theory is a distinction between crime, and event, and criminality, a characteristic of persons (Hirschi and Gottredson, 1986). Persons prone to crime tend to be active, relatively strong, unconcerned for the suffering of others, indifferent to punishment, impulsive, pleasure-oriented, and reckless. The aggressive, active, adventuresome child (whose traits may be biologically based) will be more difficult to socialize and will require more parental skill, attention, and care than children without these traits. However, because the parents will tend to share the child's traits, they will be less likely to perform the required socialization tasks. The proposed theory requires no positive explanation for criminality, but rather assumes that in the absence of socialization, the child will be high on crime potential. Crime as an event presupposes circumstances that make crime possible, e.g., the availability of goods to be stolen, damaged, or burned, and persons to be assaulted or defrauded. Other conditions bear on circumstances that encourage the potential offender, such as darkness, anonymity, and victim vulnerability. This theory allows causal variables to be sorted into those that affect the propensity to commit criminal acts and those that describe an environment conducive to such acts. The theory is discussed with reference to education policy, deterrence, and other crime-cause theories. 17 references.