ABSTRACT
The term 'temperament' describes the largely inborn normal differences in behavioural style that make a major contribution to a child's normal daily behaviour. However, temperament differences can contribute to judgements of psychopathology when there is a poor fit between them and the environment and when the traits themselves are misinterpreted as abnormal. The most concise definition of temperament is as 'behavioural style' or the characteristic way with which the child experiences and responds to environmental stimuli. It is the 'how' of behaviour rather than the 'what' (the abilities) or the 'why'. The ancient Greeks and Romans, particularly Galen, developed the humoral theory of health and temperament. Their view was that the variable mixture in the individual of blood, yellow bile, black bile, and phlegm determined whether one would be sanguine, choleric, melancholic, or phlegmatic. Despite the complete lack of scientific evidence for this theory, it dominated thinking in European culture until the 19th century.
