Which of the following emerges first?

Question

Quizplus · Accepted Answer

Smiling related to internal physiological states, such as feeling comfortable or content, is typically the first type of facial expression to emerge in infants, appearing as early as a few weeks old. Laughter in response to physical or psychological stimulation typically appears later, around 4-5 months old. Social smiles, which are smiles directed towards others and used to communicate positive emotions, also typically appear around 4-6 weeks old.

Which of the Following Emerges First