Development of Healthy Attachment

The following is a list of milestones that indicate the development of healthy attachment.

From 0-2 months: Even though infants show little observable preference for a particular caregiver, the warm, sensitive, and dependable responses of caregivers to the infant set the stage for the developing attachment relationship.
From 2-7 months: Infants tend to interact differently with primary caregivers and strangers, but in general still do not show strong preferences.
By 4-6 months: Infants begin to develop expectations of how their caregiver will respond to them when they are distressed. These expectations, based on daily experiences with their primary caregiver, are termed internal working models of attachment relationships.
Between 7-12 months: Infants show definite preferences for a small number of individuals to whom they are attached. “Stranger anxiety” may begin to emerge.
From 12-18 months: As they begin crawling and walking, infants use the person they are attached to as a secure base of attachment from which they venture out and explore the world, and as a safe haven to return to when frightened or distressed.
From 18 months to approximately 4 years of age: The attachment relationship is characterized by tolerance of separation, learning to cooperate, and balancing the need for autonomy, self-control, and exploration with the continued need for love, affection, and protection.