Final answer:
The child who demonstrates the ability to see objects as neither 'all good' nor 'all bad' and seeks attention from the primary caregiver is in the rapprochement stage of developmental object relations theory.
Step-by-step explanation:
A child who no longer characterizes objects as "all good" or "all bad" and appears to demand an increased amount of attention from the primary caretaker is described in developmental object relations theory as being in the stage of rapprochement. This phase typically occurs between the ages of 16 and 24 months when the child is redefining the relationship with their caregiver and seeks to maintain closeness while exploring their independence. They are beginning to see the caregiver as a separate individual with both positive and negative attributes, marking a shift from the earlier individuation phase where they start to develop their sense of self and autonomy. This phase follows the earlier sensorimotor stage identified by Piaget, where children develop object permanence and where stranger anxiety can emerge when a child is unable to assimilate an unfamiliar person into existing schemas.