“…(2) To what degree are the effects of undemutri-Until the late 1960s, the major strategy tion early in life irreversible, that is, is there a for field research on these questions was to "critical" or "sensitive period" during which compare retrospectively the development of the child is especially vulnerable to loss of malnourished and control infimts, but this appotential for growtii? (3) Is the simple provi-proach entailed considerable difficulties in sion of foodstuffs an effective, and cost-matching the two groups on economic and effective, intervention to reduce the inci-social background (e.g., Cravioto, Birch, De Licardie, Rosales, & Vega, 1969). Large-scale projects were undertaken in the late 1960s and early 1970s to address these problems, but they too experienced self-selection by subjects, differences in baseline measures, and complications in defining the exact nature of the interventions (Chavez, Martinez, & Yachine, 1975;Gopalan, Swaminathan, Kumari, Rao, & Vijayaraghavan, 1973;Graves, 1976;Taylor, Kielmann, De Sweemer, & Uberoi, 1978).…”