The vast, heavily forested island of Sumatra forms the southern perimeter of the Strait of Malacca. The strait is one of the most important lanes of shipping and commerce in the world, and historically a crossroads of cultural influences from the Middle East, India, China, and elsewhere in Southeast Asia and East Asia. Although nearly all of the approximately twenty ethnolinguistic groups of Sumatra are devout practitioners of Islam, they nonetheless differ strikingly from one another, particularly in their family structures.
Situated in the Special Region of Aceh the northernmost provincial-level unit of Sumatra, the more than 3.4 million Acehnese are most famous throughout the archipelago for their devotion to Islam and their militant resistance to colonial and republican rule. Renowned throughout the nineteenth century for their pepper plantations, most Acehnese were rice growers in the coastal regions in the early 1990s.
Acehnese do not have large descent groups; the nuclear family consisting of mother, father, and children is the central social unit. Unlike the Javanese or Balinese family, the Acehnese family system shows marked separation of men's and women's spheres of activity. Traditionally, males are directed outwardly towards the world of trade. In the practice of merantau--going abroad or away from one's birthplace--young adult males leave their homelands for a time to seek their fortune, experience, and reputation through commerce. This may involve travel to another village, province, or island. This maturation process among males is viewed as growing out of the domestic female-dominated world of sensory indulgence and into the male world of reasoned rationality, whose practice is expressed through trade. One model of Acehnese family life is that a woman sends a man out of the house to trade and welcomes him back when he brings home money. When he has exhausted his money, she sends him out again. Meanwhile, women and their kin are responsible for working the fields and keeping the gardens and rice fields productive.
This oscillating pattern of migration encountered some difficulties in the 1980s as increasing numbers of men failed to return to the Acehnese homeland, but instead remained and married in remote locations, such as Jakarta and Kalimantan. In addition, northern Sumatra experienced important changes because of the influx of temporary workers seeking employment in the oil and timber industries.
The term Batak designates any one of several groups inhabiting the interior of Sumatera Utara Province south of Aceh: Angkola, Karo, Mandailing, Pakpak, Simelungen, Toba, and others. The Batak number around 3 million. Culturally, they lack the complex etiquette and social hierarchy of the Hinduized peoples of Indonesia. Indeed, they seem to bear closer resemblance to the highland swidden cultivators of Southeast Asia, even though some also practice padi farming. Unlike the Balinese, who have several different traditional group affiliations at once, or Javanese peasants affiliated with their village or neighborhood, the Batak orient themselves traditionally to the marga, a patrilineal descent group. This group owns land and does not permit marriage within it. Traditionally, each marga is a wife-giving and wife-taking unit. Whereas a young man takes a wife from his mother's clan, a young woman marries into a clan where her paternal aunts live.
When Sumatra was still a vast, underpopulated island with seemingly unlimited supplies of forest, this convergence of land ownership and lineage authority functioned well. New descent groups simply split off from the old groups when they wished to farm new land, claiming the virgin territory for the lineage. If the lineage prospered in its new territory, other families would be invited to settle there and form marriage alliances with the pioneer settlers, who retained ultimate jurisdiction over the territory. Genealogies going back dozens of generations were carefully maintained in oral histories recited at funerals. Stewardship over the land entailed spiritual obligations to the lineage ancestors and required that other in-migrating groups respect this.
The marga has proved to be a flexible social unit in contemporary Indonesian society. Batak who resettle in urban areas, such as Medan and Jakarta, draw on marga affiliations for financial support and political alliances. While many of the corporate aspects of the marga have undergone major changes, Batak migrants to other areas of Indonesia retain pride in their ethnic identity. Batak have shown themselves to be creative in drawing on modern media to codify and express their "traditional" adat. Anthropologist Susan Rodgers has shown how taped cassette dramas similar to soap operas circulate widely in the Batak region to dramatize the moral and cultural dilemmas of one's kinship obligations in a rapidly changing world. In addition, Batak have been prodigious producers of written handbooks designed to show young, urbanized, and secular lineage members how to navigate the complexities of their marriage and funeral customs.
The Minangkabau--who predominate along the coasts of Sumatera Utara and Sumatera Barat, interior Riau, and northern Bengkulu provinces--in the early 1990s numbered more than 3.5 million. Like the Batak, they have large corporate descent groups, but unlike the Batak, the Minangkabau traditionally reckon descent matrilineally. In this system, a child is regarded as descended from his mother, not his father. A young boy, for instance, has his primary responsibility to his mother's and sisters' clans. In practice, in most villages a young man will visit his wife in the evenings but spend the days with his sister and her children. It is usual for married sisters to remain in their parental home. According to a 1980 study by anthropologist Joel S. Kahn, there is a general pattern of residence among the Minangkabau in which sisters and unmarried lineage members try to live close to one another, or even in the same house.
Landholding is one of the crucial functions of the female lineage unit called suku. Since the Minangkabau men, like the Acehnese men, often merantau (go abroad) to seek experience, wealth, and commercial success, the women's kin group is responsible for maintaining the continuity of the family and the distribution and cultivation of the land. These groups are led by a penghulu (headman). The leaders are elected by groups of lineage leaders. As the suku declines in importance relative to the outwardly directed male sphere of commerce, however, the position of penghulu is not always filled after the death of the incumbent, particularly if lineage members are not willing to bear the expense of the ceremony required to install a new penghulu.
The traditions of sharia and indigenous female-oriented adat are often depicted as conflicting forces in Minangkabau society. The male-oriented sharia appears to offer young men something of a balance against the dominance of adat law in local villages, which forces a young man to wait passively for a marriage proposal from some young woman's family. By acquiring property and education through merantau experience, a young man can attempt to influence his own destiny in positive ways.
Increasingly, when married couples merantau, the women's roles tend to change. When married couples reside in urban areas or outside the Minangkabau region, women lose some of their social and economic rights in property, their social and economic position becomes less favorable, and their divorce rate rises.
Minangkabau were prominent among the intellectual figures in the independence movement of Indonesia. Not only were they strongly Islamic, they spoke a language closely related to Bahasa Indonesia, which was considerably freer of hierarchical connotations than Javanese. Partly because of their tradition of merantau, Minangkabau developed a cosmopolitan bourgeoisie that readily adopted and promoted the ideas of an emerging nation state.