Explanation : Jean Piaget in his Cognitive Development Theory, gave four stages of development.
(i) Sensori-motor Stage This is the first stage during
this stage, infants are busy discovering relationship
between their bodies and the environment.
(ii) Pre-operational Stage It ranges from about age 2 to 7
years. The child in this stage is pre (before)
operations. This means child cannot use logic or
transform, combine or separate ideas.
(iii) Concrete-operational Stage This is 3rd stage and
most children will enter this stage around age of 7
years and complete prior to eleven. In this child
is capable of performing a variety of mental
operations and thoughts using concrete concepts.
(iv) Formal-operational Stage is 4th stage and begins at
about age of 11 years. In this, as adolescents
enter this stage, they (children) gain the ability
to think in abstract manner.