Final answer:
Katelyn, at twelve years old, is most likely in the formal operational stage, where abstract and hypothetical thinking, including thoughts about relationships, develops.
Step-by-step explanation:
Twelve-year-old Katelyn is most likely in the formal operational stage of cognitive development, according to Piaget's theory.In the formal operational stage, which typically begins around the age of 11, children develop the capacity to think abstractly and handle hypothetical situations. They move beyond thinking concretely about the world and begin to understand complex concepts such as love and relationships.
At this stage, they can also consider multiple outcomes and possibilities, engage in advanced problem-solving, and even start to analyze emotions and social interactions. Katelyn's interest in boys is indicative of the broader abstract thinking and emotional development that characterizes this stage.