|Early Supplementary Feeding and Cognition (Society for Research in Child Development, 1993, 123 pages)|
|II. Methodology and findings of the longitudinal study|
Composite Infant Scale. - Of the six new analyses of the infant data, only one showed an effect of treatment: Atole children had significantly higher scores on the motor scale at 24 months than Fresco subjects (see Table 3). When interactive terms were entered into the model, no significant interactions of treatment with either a composite SES variable or sex emerged.
Preschool battery. - After adjusting for all other covariates in the model (sex, attendance, and SES), a main effect of treatment was obtained at 4 and 5 years on Factor 1 scores, with Atole subjects performing significantly better than Fresco subjects (see Table 4). No differences between treatment groups on Factor 2 scores were obtained at any age.
There was a significant main effect of gender at age 4 years, with girls scoring higher than boys on the verbal factor score. When the treatment x SES interactive term was entered into the model, significant interactions at 4 and 5 years emerged on the first factor. At both these ages, SES was not associated with performance in the Atole subjects, but it was positively related to outcomes in the Fresco villages. As depicted in Figures 1 and 2, the largest differences between treatments were observed in subjects at the lowest end of the socioeconomic distribution; as SES improved, differences between groups were less evident.