According to Piaget, what is the first stage of cognitive development called?

Concept — Piaget describes cognitive growth as an invariant sequence of four qualitatively different stages. A stage is defined not by age alone but by the kind of mental operation available to the child, and the sequence moves from intelligence that exists only in direct action on the world, to symbolic thought, then to logic about tangible things, and finally to logic about abstract possibilities.

Application — The stage the theory places at the beginning is the one in which the child has no symbols yet: knowing is doing. Intelligence shows up as the coordination of what the child sees, hears and touches with what the child does - reflexes elaborating into circular reactions - and its landmark achievement is object permanence, the realisation that an object continues to exist when it is out of sight. Piaget calls this the sensori-motor stage, running roughly from birth to about two years.

Contrast — Each of the remaining stages requires a capability the sensori-motor child does not yet possess:

• Pre-operational stage - symbolic representation arrives through language, drawing and pretend play, but thinking is egocentric and centred on one salient feature, so conservation is not yet achieved.

• Concrete-operational stage - logical operations become usable: conservation, reversibility, seriation and class inclusion, but only for objects that are concrete and present.

• Formal operations stage - hypothetico-deductive and propositional reasoning appear, so the learner can reason about what is merely possible rather than only about what is real.

Answer — the sensori-motor stage.