Final answer:
A boy with low cortisol levels is most likely to engage in aggressive and criminal behavior, according to research. This is related to cortisol's role in stress response and mood regulation, while high serotonin levels often inhibit aggression, and hormonal balance typically leads to standard behavior.
Step-by-step explanation:
Based on research into the links between body chemistry and criminality, the boy who is most likely to be engaged in aggressive and criminal behavior is D) A boy with low cortisol levels. Research has linked low levels of cortisol, which is involved in stress response and mood regulation, with increased risk-taking and impulsive behavior, potentially leading to aggression and criminality. In contrast, high levels of serotonin often correlate with feelings of well-being and are thought to inhibit aggression. A balanced hormonal state is generally associated with typical behavior patterns. While high testosterone levels have often been presumed to link with aggression, studies have found no clear relationship and further research in this area is needed.
It is important to note that hormones do not deterministically cause behavior. Environmental factors, experiences, and social context also play crucial roles in influencing a person's actions and behaviors.