Social Organization. The major feature of Yezidi social structure is a three-tiered caste system.
Myur (pl., Mrit ) belong to the lay caste, regardless of the wealth or position of the individual members. Each Yezidi is the disciple of a specific sheikh or pyir, who performs certain important rituals for the disciple. Lay Yezidis must kiss the hand of their spiritual master each day. A subgroup within the Myur caste, the Jab-Nabba, had to wear woolen shirts and defend the sacred beliefs of the Yezidis.
The clergy are drawn from the remaining two castes, pyir and sheikh. They enjoy special prestige in Yezidi society. Many of the clerical ranks are inherited. The priests are typically men, but should a woman inherit a priestly office, she is treated with the same respect as that due a man. The principal ranks (which are not to be confused with the identical caste names) are the sheikhs, the pyirs, the kawwâls, and the fakîrs.
The sheikhs derive from only five families, which trace their ancestry to the pupils or brothers of the deified Sheikh 'Adî. Their houses serve as places of worship. The chief sheikh is chosen from among the descendants of the previous chief, with personal qualification as well as directness of descent factoring into the decision. He is regarded as the chief authority on spiritual matters and the interpretation of the Yezidi scriptures. In Transcaucasia, a woman can never function as sheikh, regardless of her caste.
The pyirs are priests of lesser rank who preside at religious festivals, weddings, circumcisions, etc., for which services fees are paid to them.
The kawwâls are singers and musicians—their instruments are the flute, tambourine, and drum—who perform at festivals and processions. There are also dancers ( kochak ) who serve at the tomb of Sheikh 'Adî and perform, at Yezidi festivals, a frenzied dance with their long hair untied and waving about.
The fakirs (also known as kara-bash —"black-heads"—because of the black turbans signifying their rank) are the lowest order of clergy. They perform menial tasks at the tomb of Sheikh 'Adî, such as hewing wood, drawing water, and collecting contributions for the upkeep of the shrine.
Political Organization. The Iraqi Yezidis recognize two leaders: the chief sheikh (see "Social Organization") and the Emîr al-umarâ (also known as Mîrzâ Beg), who is their chief temporal authority and representative in external affairs. The spiritual and secular leaders of the Transcaucasian Yezidis are drawn from the sheikh caste.
Social Control. Many foreign visitors have noted the dignified and orderly comportment of the Yezidis, said to contrast favorably with that of their neighbors. Respect for parents and the elderly is considered an important virtue.
Conflict. The severest punishment recognized by the Yezidis is excommunication, which only the chief sheikh, with the approval of the tribal chief, can decree. Blood feuds occur among the Yezidis, as among the Muslim Kurds.