4 – 7 months

Enjoys social play, interested in mirror images, responds to other people’s expressions of emotion and appears joyful often, responds to own name, begins to respond to “no”

By end of 1 year

Shy or anxious with strangers, cries when mother or father leaves, enjoys imitating people in his play, shows specific preferences for certain people and toys, tests parental responses to his actions during feedings

By end of 3 years

Imitates adults and playmates, spontaneously shows affection for familiar playmates, can take turns in games, understands concept of “mine” and “his/hers”

By end of 4 years

Interested in new experiences, cooperates with other children, plays “Mom” or “Dad”, increasingly inventive in fantasy play, dresses and undresses, negotiates solutions to conflicts