Final answer:
Infants do not show implicit awareness of physical attractiveness as a social category, while they do for race, age, and gender.
Step-by-step explanation:
Infants show implicit awareness of various social categories, however, the category that they do not show an implicit awareness for among the options provided is physical attractiveness. Studies and observations indicate that very young children can discern differences and show preferences based on race, age, and gender. These categories provide essential cues about individuals that are processed automatically, often leading to the formation of stereotypes and prejudices. On the other hand, concerns about physical attractiveness, although prevalent in socialization, especially in the context of femininity and expectations placed upon girls, do not constitute an implicit category infants are aware of in the same way as the other three.