Final answer:
Your son has not yet developed self-awareness, indicated by trying to grab the hat in the mirror, not recognizing his own reflection. This awareness typically begins to develop around 18 months of age and is a key milestone in cognitive development.
Step-by-step explanation:
The aspect of consciousness that your son has not yet developed is likely self-awareness or self-concept. This is evident from the behavior of trying to grab the hat in the mirror, which indicates that he does not yet recognize his own reflection as himself. According to developmental psychology and studies such as the mirror test developed by Amsterdam in 1972, children start to develop self-recognition at around 18 months old. Before this point, babies may view their reflection as another child rather than themselves. Understanding that the reflection is one's own is part of cognitive development and is closely connected with advances in other cognitive abilities, such as object permanence and theory of mind (TOM). These cognitive milestones are part of the normal developmental stages outlined by theorists like Jean Piaget.