An anthropologist observes a young man holding a door open for a woman entering a building. from the perspective of someone studying gender, how can this be interpreted?

The event could be interpreted as: gender perfomance

Gender performance refers to a set of gesture, way talking, or words that used in language that set as a norms for specific gender by society. In western society, this could be seen in behaviors such as holding doors for women, women not expected to eat big meals at social setting, women not using foul language, etc.