Book Reviews : N. McArthur: Island Populations of the Pacific. A. Stevenson, E. Martin and J. O'Neill: High Living: A Study of Family Life in Flats. J. E. Meade and A. S. Parkes (eds): Genetic and Environmental Factors in Human Ability. H. L. Koch : Twins and Twin Relations. R. B. Edgerton: The Cloak of Competence-- Stigma in the lives of the Mentally Retarded: Island Populations of the Pacific. Norma McArthur, Australian National University Press, Canberra, 1967, pp. xvi + 381. $9.60