Which milestone is typical by 4 months in terms of social engagement?

• A. Laughs and vocalizes; responds to social cues
• B. Sits without support
• C. Walks
• D. Speaks in sentences

Answer: (A)

By four months, babies become noticeably more socially engaged. They start laughing and vocalizing more, and they actively respond to people around them—making eye contact, following voices, and smiling back during interactions. This shows a growing ability to engage with others and interpret social cues, which is exactly what this age is known for. The other milestones belong to different domains or later times: sitting without support typically happens around six months, walking around a year, and speaking in sentences develops well after the first year. So the combination of laughing or vocalizing and responding to social cues best fits the four-month stage.