Effects of calorie and protein deficiencies early in life on the subsequent learning ability of rats.

I . The effect of malnutrition early in life on the subsequent learning ability of male rats was studied when they were malnourished and after they had been rehabilitated. The HebbWilliams Test of animal intelligence was used. 2. Animals were malnourished from weaning, from birth, or from conception. 3. The rats used for tests were fed on a ( I ) low-protein, (2) low-calorie, or (3) stock diet. 4. The mean number of errors made by all groups of malnourished animals, tested when they were 13 weeks old, was always greater than that made by the corresponding controls. The same was true after rehabilitation for 5 weeks.