Hughes investigated egocentrism in his 'policeman doll study'. Describe this study.

Hughes' (1975) study aimed to create a test for egocentrism that made more sense to children than Piaget's three mountains task. The procedure involved showing children aged 3.5 to 5 a model of two intersecting walls that formed a cross shape, creating four sections. The child was introduced to two policeman dolls and one 'boy' doll. The child was first asked to hide the boy doll from one policeman. After they could do this, a second policeman doll was introduced. The key task was for the child to hide the boy doll in a section where neither of the two policeman dolls could see him. Hughes found that 90% of the children were able to correctly hide the boy doll from both policemen. He concluded that children are able to see the world from another person's perspective at a younger age than Piaget suggested, as long as the task is meaningful and makes sense to them.