Piaget’s theory of cognitive development involves four stages. Of these is the sensorimotor stage, the first stage happening from birth to about two years. It is a stage with rapid cognitive growth where infants enhance their world understanding through trial and error using their actions and senses. These actions become progressive in relation to the surrounding environment following the child’s participation in the process of accommodation and assimilation.
Tertiary circular reactions as contained in Piagetian theory is an action of an infant that creatively modifies previous schemes to acclimatize to requirements as posed by new circumstances. These reactions take place near the end of the sensorimotor development stage, normally about the start of the second year. These reactions vary from earlier child behaviours and show that it can grow new schemes to attain the desired goal during the developmental stage. They are also known as the discovery of new means by way of active experimentation.