Your baby's social and emotional development in year 1
Your baby begins experimenting with grins and grimaces in the first month.
By month 2 or 3, your baby has mastered the social smile, realizing it gets attention. The more your baby engages with you, the less time she will feel overwhelmed by internal sensations, such as hunger, gas, or fatigue.
By a few months into the first year, your baby should enjoy playing with familiar people and become more communicative and expressive. She might smile at a reflection or start to scream to show annoyance, and assert preferences for certain people and specific toys. Additionally, your baby might be fearful of new situations, but with your help, she will be able to learn and accept new settings.