The Kurds are a distinct, non-Arab ethnic group, mostly Sunni Muslims, with their own language, customs, dress, and ways of life. Originally the Kurds formed a mostly rural society. Traditional tribal villages included nomadic or seminomadic groups, but an increasing number of Kurds now live also in towns and work at various urban trades. Yet most Kurds, urban and rural alike, still associate themselves with specific tribal groupings. Throughout Kurdistan, marriage between cousins, or at least within the tribal clan, is preferred, and marriage with the father's brother's daughter is regarded as ideal. Such marriages are, nevertheless, accompanied by the payment of a bride-price (a substantial sum of money) to the father of the bride. These customs were prevalent among the Kurdish Jews as well. Such marriages assured the strengthening of kinship ties and the obedience of the bride to her husband and her mother-in-law, who was the "boss" in the extended family, in which all lived under the same roof. In the case of rich families, it kept the family's wealth within the family. It was usually beneficial for the bride as well: she did not have to wander to another tribe or village, and, as a relative, she was treated kindly and favorably. She stayed close to her parents and her previous home, which was an important moral support for young brides, who were often married at the age of 15 to 16, sometimes to much older husbands. Monogamy was the common norm, although some practiced polygamy. Soon after the wedding, the new bride had to be quickly "incorporated" into a very busy joint-family household, succumbing to endless chores and hard work. She was expected to bear a child, preferably a son, during each of her fertile years. There was a high rate of child mortality, however, and the chances of survival for the newborn were about fifty-fifty. Even though Kurdish society is patriarchal and patrilineal ties are very important, Kurdish women enjoy more freedom and a wider participation in public life than do rural Arab, Persian, and Turkish women. Kurdish women are also freer in their behavior toward males and rarely wear the veil, which is commonly worn by women in the Muslim world.