In the late 1960s there was some evidence that social mobility was slowing down and that the society was beginning to stabilize into self-perpetuating social groups. With the slowing of economic growth the number of job openings in the higher levels has been reduced, and the intelligentsia can satisfy from its own ranks most of the demand for professional and managerial personnel. The social mix of students in higher education in the late 1960s was far from representative of the population as a whole--only about 39 percent of the students were from peasant or worker families, although these groups constituted about 78 percent of the population. In spite of all their admission advantages, children of lower income families have not been able to compete effectively with those of higher income background. Given education as a main channel of mobility, disadvantage in educational opportunities means lower possibility for social advancement. Political loyalty, however, can still override all other considerations and propel a person up the social ladder. Membership in the party, therefore, continues to afford considerable advantage. OTHER SOCIAL GROUPS Bulgarians are not by nature joiners. Formal organizations were of little significance in national life before the 1940s. Although a wide variety of groups existed, mostly in the towns and cities, membership was generally small and was based on strictly utilitarian considerations. Individuals joined to derive the benefits provided by the organization, such as easy credit, professional standing, use of libraries and other cultural facilities, or use of sports facilities. Few members were actively involved in the operation or the activities of the organizations to which they belonged. Banding together for a common purpose, however, was far from alien to Bulgarian culture; but social organizations and informal groupings that emerged from such banding together usually were based on kinship or on close personal ties. The most important formal traditional organization was the _zadruga_ (see The Family, this ch.). In a less formal vein, wool-cording and spinning bees were important features of rural social life before collectivization. In fact, many agricultural activities, such as hoeing and harvesting, were undertaken by groups of friends and relatives who joined together to take turns working on each other's land. This joining together for the accomplishment of necessary tasks served an important social, as well as economic, function. While working together in such groups, individuals exchanged ideas, passed on information and, thereby, either reinforced each other's traditional values and mores or helped develop new ones.