Which of the following milestones of emotional development typically occurs first?

Social referencing involves looking to caregivers or others to gauge how to respond to unfamiliar situations. This behavior typically emerges later, around 10 to 12 months of age, as infants begin to seek emotional cues from those around them. Therefore, it is not one of the earliest milestones in emotional development.

Emotion-centered coping refers to strategies used to manage emotional distress, which typically develops after children have a better understanding of their emotions and those of others. This usually occurs in later stages of childhood, making it a more advanced milestone than a social smile.

Empathy is the ability to understand and share the feelings of another, which usually develops in toddlers and older children, around ages 2 to 3. This skill requires a level of social awareness and cognitive development that surpasses the very early stages represented by a social smile.