<Li> An early form of personality type indicator theory was the Four Temperaments system of Galen, based on the four humours model of Hippocrates; an extended Five Temperaments system based on the classical theory was published in 1958 . </Li> <Li> One example of personality types is Type A and Type B personality theory . According to this theory, impatient, achievement - oriented people are classified as Type A, whereas easy - going, relaxed individuals are designated as Type B . The theory originally suggested that Type A individuals were more at risk for coronary heart disease, but this claim has not been supported by empirical research . </Li> <Li> One study suggests that people with Type A personalities are more likely to develop personality disorders whereas Type B personalities are more likely to become alcoholics . </Li> <Li> Developmental psychologist Jerome Kagan is a prominent advocate of type indicator theory . He suggests that shy, withdrawn children are best viewed as having an inhibited temperament, which is qualitatively different from that of other children . </Li>

Who describe different types personality based on glands