Describe one theory of cognitive development.

Piaget's theory of cognitive development poses that there are 4 sequential stages of development. The child moves through the stages as they mature. The first stage is the sensorimotor stage (0-2 years old approximately). This stage is characterised by early reflex activities, such as sucking. These activities allow for the child to develop the ability to coordinate sensory and motor activity. The child is aware that objects exist even though they mat be out of sight (this is called object permanence). The pre-operational stage occurs between ages 2 and 7 years. This stage is characterised by the use of symbols, such as language, but not adult logic. Transductive reasoning is used in this stage. For example, the logic is centred on one aspect of something and this aspect cannot be applied to other situations. So the child may know that a dog has four legs, therefore they may think if another animal has four legs it must also be a dog. Thinking is egocentric, so the child has difficulty taking the viewpoint of others. The third stage is the concrete operational stage, which occurs between 7 years and 11 years of age. In this stage, the child can use mental operations (logic/rules) for concrete tasks, but not abstract tasks. So for example, physical objects (concrete). Children also gain the ability of conservation (understanding area, volume, number and orientation). Thus, they can solve concrete problems but cannot think abstractly, or hypothetically. Finally, there is the fourth stage; the formal operational stage. This occurs from 11 years onwards. In this stage, abstract and systematic through is developed and possible. The child can therefore logically test hypotheses.Adaptation processes allow for the transition from one stage to another. It is important to know the definition of these terms.Assimilation is using an existing schema (knowledge) and applying this to a new situation or object. Accommodation is when the existing knowledge does not work when applied to the new situation, and therefore needs to be adapted and changed to suit and deal with the new situation. When a child's schemas (units of knowledge) can deal with most new situations through assimilation, equilibrium occurs. If new information cannot be dealt with by using existing schemas (through assimilation), this means that the state of disequilibrium occurs.