Three specific theories of delinquent and criminal behavior positing a neurological cause are discussed. Arousal theory suggests that delinquents and criminals have suboptimal arousal levels. Thus, they are neurologically inclined to seek stimulation in a variety of ways and to tolerate more pain in satisfying their need for stimulation. Seizuring theory contends that violent and explosive aggression and other emotionally impulsive acts of criminality may be caused by subconvulsive brain seizures. Hemispheric functioning theory asserts that involvement of the more implusive 'nonlinguistic' right hemisphere of the brain in higher thought may prevent some individuals from paying attention to linguistic commands, thus making them more cynical and defiant of efforts to control them and their environment. The influence of male hormones in brain functioning and behavior is also discussed. The approach discussed, called a genetic, environmental, neurologically meditated interactionist (GENMI) approach, assumes that th physical-chemical functioning of the brain is responsible for all human behavior and is the result of the interaction of genetic and environmental factors. Unlike behaviorists, adherents of GENMI study how specific brain functioning may alter behavior. The author argues that behaviorism and GENMI can work together productively in criminology. 142 references.