Skeels and Dye Study
...he group had an average I.Q. of 64 with a range of 35-89. A year and a half later their IQS had increased on the average of 27.5 points. As a control group Skeels and Dye used twelve children who were retained in the wards. These 12 children had an initial average I.Q. of 87.6, ranging from 50-103. After a year and a half this group who remained in the orphanage under a non-stimulating environment lowered their IQ by an average of 26.2 points. Two follow up studies were made - one after three years and one after 21 years. In the first they found that the children retained their accelerated rate of development in foster homes while the control group, those who had stayed in the orphanage, continued to drop in intellectual performance. In the second study...