Infants were observed in 38 homes in a high-density suburb in Zambia over the period from 4 months through 12 months. The major focus is upon the mother-infant relationship and the way in which it structures the infant’s world. A major difference between Zambian infancy and infancy in the United States is that the Zambian infant spends most of his time in close physical contact with the mother, since he is carried on her back in a sling. The effects of this practice on motor, cognitive and social development are discussed.