Final answer:
A student hesitating to leave a class in the middle of a lecture exemplifies an implicit rule, which is an unspoken norm that dictates appropriate behavior within a society.
Step-by-step explanation:
The student hesitating to leave a class in the middle of a lecture is an example of what social psychologists would call an implicit rule. These are the unspoken, unwritten, but understood norms of a community, which govern the behavior of its members without the need for explicit statements. Implicit rules are a form of social norm that provides guidelines on how to act in a given situation based on the shared beliefs, values, and practices of a society. As opposed to explicit rules, which are formally communicated and documented, implicit rules are learned through social interaction and cultural experiences. They are vital to maintaining social order and help individuals feel secure and 'normal' within their culture.