•Freud described the personality as being tripartite i.e. composed of three parts: the id, ego and superego.•Each part of the personality demands gratification, but is frequently in conflict with the other parts.•Experience/conflicts in childhood shape the development of the three parts, which affects how a person behaves. E.g. If a person's superego is too strong, they are seen as rigid, pompous or self righteous. Or if a person's id is too strong, they are seen as delinquent, antisocial or self-centred.