During this month, muscles get more flexible and primitive reflexes begin to give way to voluntary movements. Babies will begin to open their hands and look at them with interest, and will frequently bring them to their mouths. They will also start hitting objects near them. Their head control continues to improve and they will be able to lift their heads for a few seconds when doing tummy time.

They produce a variety of sounds (often guttural), especially as a reaction to someone talking to them lovingly. They are aware of the sounds that they produce and enjoy repeating them multiple times. The amount of time that they spend crying starts to decrease.

Their personality and temperament begin to emerge. They will start developing a social smile that no longer requires touching or tickling to elicit a response. They smile and make various noises while moving their arms and legs to express happiness.