What is a sign that a 3-month-old is developing a healthy social emotional response?

A key indicator that a 3-month-old is developing a healthy social emotional response is smiling in response to familiar faces. This behavior reflects the infant's ability to recognize and respond to social stimuli, demonstrating an emerging bond with caregivers and others in their environment. Social smiles typically begin to appear around 6 to 8 weeks of age, and by 3 months, infants show a clear preference for familiar individuals, indicating an early capacity for emotional engagement and connection.

The other options provided reflect developmental milestones but are not primarily indicators of social emotional responses. Reaching for objects is more indicative of developing fine motor skills and hand-eye coordination. Cooing and gurgling sounds relate to early language development and vocalization rather than social interaction. Looking around at surroundings indicates curiosity and cognitive development, but it does not specifically signify an emotional or social response. Thus, the act of smiling in response to familiar faces is the most direct sign of healthy social emotional development in a young infant.