In a study to determine whether or not culturally deprived children develop at progressively greater deficits in intellectual functioning during the ages of 15 months to 3 years, tutors provided 15-month-old infants with intellectual and verbal stimulation one hour daily, five times a week until they were 36 months old. The subjects consisted of Negro males from homes that met two of the following three criteria: (1) family income was $5,000 or less, (2) mother's formal education was less than 12 years, and (3) mother had been an unskilled or semiskilled worker. The experimental group contained 28 children and the control group numbered 30. Pretests on the Bayley Infant Scales showed the controls slightly superior (but not significantly) to the experimentals at 14 months. At 21 months, the experimentals had gained significantly (.05 level). Posttesting on the Stanford-Binet at ages 27 and 36 months showed experimentals were significantly superior to controls at the .01 level. When the subjects were 36 months old, the Peabody Picture Vocabulary Test and Johns Hopkins Perceptual Test showed that the experimentals were significantly superior at the .01 level; the Aaronson-Schaefer Preposition Test also showed gains but not at a significant level. (JS)