The people of the New Guinea highlands have been the subject of many recent studies by anthropologists. Discovered less than 50 years ago, observers have been able to describe many facets of their pre-contact social organization and cultural patterns. The first white men in the highlands were astonished at the intensive agriculture, population density, and community size of these people, long isolated and connected to the outside world by trade links with intermediaries of shifting agriculturalists living in small hamlets. Some of the highland and marginal peoples are similar to other inland New Guinea peoples-living in hamlets or small villages, with shifting cultivation, low population density, small language and cultural units, practicing sister exchange marriage or having exogamous local groups of less than 50 members. But in the high valleys of large rivers and on the slopes at altitudes of 5,000 to 7,500 feet (I,500-2,700m), there are settlements of intensive sweet potato cultivators with domestic pigs, of which thousands are killed in large ceremonies. Most of the area is occupied at low to medium density by cultivators practicing agriculture with some intensive techniques. The staple crop of sweet potato, technology, and other cultural characteristics are fairly common throughout a region about 6o0 miles long. Village settlements are found mainly in the eastern part; the form of settlement in other parts usually being a men's house and dispersed homesteads or houses clustered in hamlets. Whereas coastal and inland Melanesian language and cultural groups are fragmented into small separate groups, some language groups of over Ioo,ooo are found in the highlands. Chimbu, Dani, Enga, and Kapauku each have a densely populated, competitive, expanding core area of intensive agriculture in the ecologically most favorable places with smaller and more dispersed groups in the hinterland. This development may be in process in Mt. Hagen, Huli, Kakoli, and parts of Chimbu and Eastern Highlands Districts. These differences have come to light through ethnographic, archaeological, demographic, medical, and geographic studies in the past twenty or so years. As new areas are studied and findings published, the increasing body of information suggested some statistical tests of