Tertiary circular reactions stage
A 17-month-old child would be expected to be in tertiary circular reactions stage, according to Piaget.
Tertiary circular reactions stage is a sub stage under the sensorimotor stage which is the first of the four stages in Piaget's theory of cognitive development. Tertiary circular reactions stage is a phase of fast cognitive growth which extends from 12months to 18 months. During this stage, children experiences a time of trial and error by using their actions and senses.