There are four middoth in deoth (temperaments): easily angered and easily pacified — his gain is negated by his loss; angered with difficulty and pacified with difficulty — his loss is negated by his gain. [If one is quickly angered by all things, even though he is easily appeased, his loss is more than his gain. For most of his acts are defective in that he is easily angered over everything. But if one is angered with difficulty, even though he has the evil middah of being pacified with difficulty, his (relatively) small loss, being pacified with difficulty, is negated by his (relatively) greater gain, being angered with difficulty, so that most of his acts are praiseworthy. Some versions are the opposite of this; but this seems to be the correct version.]; angered with difficulty and easily pacified — a chasid; easily angered and pacified with difficulty — a wicked one.
Mishneh Torah, Human Dispositions
Each and every one of the sons of man has many innate tendencies which differ one from the other and which are extremely afar. There is one man of a feverish temperment, constantly vexed, and there is another man of a calm disposition, without angry moods whatever, and if he does show anger it is but one bit of anger in many years; one man is overmuch supercilious, and another man is extremely unobtrusive; one is sensual, whose being is never stilled by the pursuit of propensity, and one is so pure-hearted that he feels no craving even for the barest necessities of the body; one's being is so greedy that the world's money will not satisfy him, as the subject is spoken of: "He that loveth silver shall not be satisfied with silver" (Ecc. 5.10); and one's being is so restrained that he considers enough even part of the little which is insufficient for his need and he will not pursue to attain all needs; one suffers hunger in his effort of hoarding and does not eat a cent's worth of his own without great torture to himself, and another wastes his money with his own hand deliberately. And of such ways are all the rest of the tendencies, as the optimist and pessimist, miser and philanthropist, cruel and merciful, coward and stout-hearted and the like.