Which of the following is NOT a stage of attachment development according to the outlined ages?

Cooperative play is not classified as a stage of attachment development. In the context of attachment theory, stages are typically characterized by the emotional bonds and behaviors that develop between infants and their primary caregivers.

Indiscriminate reactions describe an early stage where infants show no specific preference for any caregiver, responding similarly to all. Active closeness refers to the stage where infants begin to show strong preferences for particular individuals, usually their primary caregivers, seeking proximity and showing separation distress. Clear attachment denotes a more secure attachment where the child actively seeks out the attachment figure and feels safe in their presence.

Cooperative play, on the other hand, is an interaction that typically emerges later in development, around the preschool years, when children engage in shared activities, demonstrating social skills and cooperation with peers. This is more concerned with social interaction and peer relationships rather than the foundational emotional connections established in the earlier stages of attachment. Hence, it is not recognized as part of the attachment development stages outlined for infants and toddlers.