We review a variety of theories that have been proposed to explain why adults become sexually interested in and involved with children. All the theories appear to be directed to explaining one of four factors: (a)emotional congruence—why the adult has an emotional need to relate to a child; (b)sexual arousal—why the adult could become sexually aroused by a child; (c)blockage—why alternative sources of sexual and emotional gratification are not available; or (d)disinhibition—why the adult is not deterred from such an interest by normal prohibitions. We illustrate how these four factors can be combined to explain more of the diversity in pedophilic behavior than is usually explained by single factor theories. We also introduce the idea of viewing types of pedophilia on a continuum rather than in the traditional way of treating them as dichotomies.