The earliest data on psychiatric disorders among the Maori population of New Zealand were provided in a classic study by Ernest Beaglehole (1939). Beaglehole compared hospital admission rates for psychosis for the Maori and the New Zealanders of European origin (Pakeha) during an 11-year period from 1925 through 1935. The unadjusted rate of first admissions per 100,000 population was 31.0 for the Maori. The corresponding rate for Europeans was 57.7. Because the Maori population was significantly younger than the European population, Beaglehole also determined a rough weighted rate for the year 1926 based on the population over 16 years of age. The results show a weighted rate of 41.9 per 100,000 for the Maori as opposed to 83.7 for the Europeans. After giving consideration to differences between Maori and Europeans in socioeconomic status and urban vs. rural place of residence, Beaglehole concluded "that incidence of psychosis is definitely lower among the Maori as compared with the European cultural group in New Zealand" (Beaglehole (1939)).World War I1 provided some further evidence suggesting that the Maori were less vulnerable than the Europeans to the development of psychiatric disorders. The Maori adapted well to military life and the incidence of combat reactions among the Maori soldiers was lower than that of the Europeans. Moreover, in the postwar period there were fewer pension claims from the Maori for combat-related psychiatric disorders (Stout ( 1954)).During the time period studied by Beaglehole, the Maori had been exposed to the European culture for more than a century and a half. The continuing acculturation had produced major changes in the Maori way of life. However, the Maori were a rural-dwelling people (in 1936 only 9.3% of the Maori lived in urban areas), and as such, were to some degree isolated from the European culture (McCreary (1968)). This isolation combined with a desire on the part of many Maori to maintain the traditional social organization, value system, and customs had a dampening effect on the process of acculturation, (Note 1, Appendix). Thus, at the close of the decade of the 1930's, a Maori culture remained which was in many ways distinctly unique and separate from the dominant European culture.