To the older writers, the various types of personality were distinguished according to the dominant “humour” of the body, and mankind was divided into four groups, corresponding to the four humours recognized by them. The sanguine person, in whom the blood was the dominant humour, was supposed to be light, superficial and accommodating. The melancholic, in whom black bile, whatever that was, dominated, represented the deep, self-involved, slow moving person-the strong silent man. The choleric person, with yellow bile dominant, was passionate, strong, and possessed of an active imagination; while the phlegmatic type, dominated by the colourless thick phlegm was dull, cold and slow-the “bromide” of a recent phraseology.