From birth, a baby has certain reflexes, especially the need to suck and the grasping reflex. Sucking is a natural, innate requirement in infants. Sucking helps babies to be reassured and sleep.
The grasping reflex only appears during the first few months of the baby's life, a baby bends fingers when an object is placed in its hand.
At birth, a baby has weak muscle tone and cannot support its head. This is why the head must be supported during the first few months.
About 4 months, the baby can lift up its head when it is lying down on its stomach, he/she starts to change position him or herself, on the back, he/she can roll on to its side. Finally, he/she can turn its head in the direction of an object.
About 5-6 months, the baby can hold a toy between its fingers and hold on to its feet.
From birth, the infant has a bond with its mother, it is not aware that it is a separate entity from its mother.
The baby expresses its needs: hunger and discomfort by crying and screaming.
About 3 months, he/she starts to smile and express its joy with little squeals. This is the onset of social communication. He/she starts to babble.
Between 4 and 6 months, the baby starts to be aware of its surroundings: it tries to attract attention, discovers the pleasure of playing and gets angry when it does not get what it wants. From a language perspective, he/she has sounds like "areuh" and "dada".