Level of moral reasoning refers to the ways that people think about and perceive right or wrong. Kohlberg’s theory of moral reasoning has been applied to many areas, including crime. It is a developmental theory that looks at the ways in which individuals grow in their understanding of moral decision-making and behaviour. Kohlberg argued that this happens in a staged process where moral reasoning becomes more complex and abstract as a child ages. Importantly, he argued that it is usually complete by the time the child is 9 or 10 years old, which is in line with the age of criminal responsibility in the UK, which is set at 10 years old.