Using a modified time-sampling procedure, 20 primiparous and 20 multiparous mothers were observed while breast-feeding their 48-hour old infants. In comparison with multiparous mothers, primiparous mothers (1) spend more time in non-feeding activities, (2) spend more time feeding male infants, (3) change activity more frequently, (4) provide more stimulation for their infants, (5) talk to their infants more, far more with female infants, and (6) smile more at female infants. Infants of primiparous mothers spend less time attached to the nipple, and when attached, they spend less time sucking. Longitudinal observations revealed that, for the primiparas, the number of weeks the infants were breast-fed was related to the amount of time the mothers talked to the infants at the two-day feeding observation. (Author)