1 - LEVEL SENSORY-MOTOR (FROM 0 TO 18 MONTHS)
This is the period of development before language.
One can call period "sensorimotor" because at the very beginning of his life, the infant still has neither thought nor emotion (feeling) linked to representations that suggest people or objects in their absence. It has not memory.
At this stage it is a little person who is connected to his mother, who often eats and sleeps, and lives in the sensation of pleasure. In case of discomfort, he cries to express his dissatisfaction.
On the physical level, since it grows quickly will double its size during the first year.
On the engine, it also makes a lot of progress: when the infant is unable to control his movements (he moves by reflex movements, involuntary) to 2-3 months, it puts things in their mouths, the greenhouse with his hands and already plays with his hands and clothes. It is also able to smile, he is attentive to faces, it chirps and begins to change her tears according to its needs. Around 6-8 months, it is able to sit alone, he better control his hands, he sings (sound) at the sight of his own image in the mirror.
It is now coordinating their actions to make the object he sees and wants. This is the beginning of intentionality and the threshold of intelligence.
To 9-12 months, it reacts with strange faces, he took his first steps, and he improves his knowledge of surrounding objects.
Between 12 and 18 months, he walks alone, can open a locked door and begins his first experiences such as discovering a hidden object it recognizes. It thus acquires what is called in psychological terms the "object permanence": the object continues to exist in the mind of the child even if he no longer sees it. It's sort of the beginning of memory.
At this age, the child is able to recognize themselves in a mirror as a whole person.
He also began to make connections between words and objects or pictures, it becomes able to pronounce the first words and identify body parts (nose, eyes ...). It is the emergence of language.
At the age of 2 years, the surrounding world becomes permanent in the mind of the child, unlike his original universe that is without objects as real objects are no longer before his eyes.
At the end of this period, the child is able to perform many actions, including gestures and increasingly accurate. He understands and interprets the surrounding world by imitating the sounds, people and things when they present themselves to him.
In summary, this first period called sensorimotor, leads the child to a structuring of the universe restricted to a practical level, the sensory-motor intelligence organizes reality by building broad categories of action patterns that are of the permanent object, space, time and causality. These are the substructures of these future concepts.
During the first 18-24 months occurs a kind of "revolution" in the mind of the child; more precisely a decentering general compared to itself, such that the child ends up as an object located among others in a universe of persistent objects, structured spatio-temporal seat of a causal and both spatial and objectified in things.
Experience to understand:
Around 5-7 months, when the child will pick up an object and then covered it with a cloth, the child simply removes his hand already outstretched. If it is an object of special interest (bottle or blanket), it will begin to cry or yell of disappointment: he reacts as if the object had resolved. At this age, although it can be assumed that in the mind of the child being gone is still there, it fails to solve the problem of the search and raise the screen.
Around 7-8 months, when the child begins to look beneath the screen, one can control the following: cache the object A to the right of the child, who is the research and then, under his eyes, move and hide the object B, to the left of the child when he saw the object disappear in B (as a cushion), then it happens often that the research as if A the position of the object depended previously successful actions and not its autonomous and independent movements of the action itself.
Only about 9-10 months that the object is sought in relation to its own movements.
Thus we understand that using trial and error and multiple experiences growing up the child appropriates a more accurate representation of the real world.