Cognitive psychologists believe that the most important part of acquiring sex/gender identity lies in the child’s growth and understanding of what male/female means. This can be determined by Kohlberg (1966) who suggested that children need to develop an understanding of gender before they can develop a gender identity of their own and puts forward a stage theory of gender development. His theory proposes that a child’s understanding of gender progresses in stages; at each successive stage, the child thinks in characteristic ways about gender. As the child moves through the stages their understanding of gender becomes more complex, he proposed that children only acquire an understanding of these concepts when they are “ready” (have reached the relative stage). The first stage is “gender identity”, which is usually reached by the age of 2 years and at this stage the child is able to correctly label its own sex. The second stage is “gender stability”, which is usually reached by the age of 4 years. At this stage the child realizes that gender remains the same across time, however, their understanding of gender is heavily influenced by external features like hair and clothing. A boy at this stage might say that if he put a dress on he would be a girl. It is not until the third stage “gender constancy” that the child starts to understand that gender is independent of external features; this stage is usually reached by the age of 7 years. At this stage Kohlberg predicted that children will pay more attention to the behaviour of same sex models than those of children in the earlier stages.
All stages need to be completed before achieving “gender constancy” and once this has happened then “schemas” are formed. A “schema” is where the child sorts out knowledge of male and female into categories, helps them to organise new information and understand the world around them. Martin and Halverson (1983) suggest