Final answer:
Most adult Americans are believed by Kohlberg to operate at the conventional and postconventional stages, where they follow societal norms and formulate personal moral principles.
Step-by-step explanation:
Lawrence Kohlberg proposed that most adult Americans operate at the conventional and postconventional stages of moral development. The conventional stage is characterized by an adherence to social rules and norms, often motivated by the desire to be perceived as a good person in the eyes of others. This stage is characterized by a concern for self and others, and individuals in this stage conform to societal norms and laws. They consider what society considers moral and immoral when making decisions. In contrast, at the postconventional level, individuals reason based on abstract principles that can transcend societal and legal norms, formulating a personal sense of justice and rights. This development occurs after the individual has the capacity for formal operational thought, and only a few fully achieve this stage of moral reasoning.