Final answer:
Doug is in the formal operational stage of Piaget's cognitive development theory, which begins at age 11 and involves abstract reasoning and dealing with hypothetical situations.
Step-by-step explanation:
Piaget's Stages of Cognitive Development
According to Jean Piaget's theory of cognitive development, which proposes that thinking evolves through a series of stages, Doug would be located in the formal operational stage. This stage begins around age 11 and continues into adulthood. Children in this stage move beyond thinking only about concrete events to dealing with abstract ideas and hypothetical situations. They are able to employ abstract reasoning to problem solve, consider alternative solutions, and systematically test their ideas.
Piaget's final stage exemplifies a significant shift in cognitive abilities, allowing for more sophisticated thought processes characteristic of adolescents and adults. Hence, Doug, being older than 11, would be capable of formal operational thought. However, other developmental psychologists have suggested the existence of a postformal stage of cognitive development where logic is integrated with emotion and context-based decision making.