The choleric man has a strong will, is bold, courageous, with an urge to action. Alexander the Great, Hannibal, Caesar, Napoleon, for example, were cholerics. This type of character shows itself even in childhood, and a child with this temperament will take the lead in childhood games.
The melancholic man is very much occupied with himself and hence is apt to keep himself to himself. He does a lot of thinking, particularly about the way in which his environment affects him. He withdraws into himself, tends to be suspicious. This temperament, too, is apparent in childhood: a child of this type does not like to display his toys; he is afraid something will be taken away from him and would like to keep everything under lock and key.
The phlegmatic man has no real interest in anything; he is dreamy, inactive, lazy, and seeks sensuous enjoyment.
The sanguine man, on the other hand, gets easily interested in anything but he does not stick to it; his interest quickly fades; he is continually changing his hobbies.
These are the four basic types. Generally a man is a mixture of all four, but we can usually discover the fundamental one.
Source: Rudolf Steiner – GA 95 – At the Gates of Spiritual Science: Lecture VII – Stuttgart, 28th August 1906