Normal, first-born children of two-parent, self-supporting families (N=60) were divided into three groups at birth: control, mothers receiving a specific language stimulation program, and both parents receiving the program simultaneously. Infants whose parents received simultaneous training exhibited the greatest gain over 4 1/2 months in Bayley…

Infants judged to be at risk for subnormal intellectual growth were randomly assigned to experimental and control groups which varied as to educational curriculum activities. Two types of evidence, group differences and parent-child IQ correlations, demonstrate the importance of early environments in intellectual development. (Author/RD)