The present study examined longitudinally the origin of a prior finding that mothers who perceived their infant's temperament as either "easy" or "difficult" exhibited a differential psychophysiological response pattern. Additionally examined were the pattern's behavioral correlates and relation to infant-mother attachment. Participants were 57 Caucasian primiparous mothers of middle to upper middle class background and their healthy infants. Measures included physiological responses to crying, (pre- and post-delivery), child rearing attitudes, Carey's Revised Infant Temperament Questionnaire, observations of feeding and play, and assessment of attachment. Findings indicated that mothers who later rated their own infant as temperamentally "difficult" displayed prior to delivery a pattern of greater physiological arousal in response to an unfamiliar infant's cry and showed more punitive child rearing attitudes. The pattern was similar when mothers' infants were 5 months old, when heart rate responses to their own infant's cry again differentiated the two groups. Few behavioral differences between the two groups were found. All "easy" infants were securely attached to their mothers, whereas a large proportion of the "difficult" infants were anxiously attached. No association was found between maternal temperament ratings and infant characteristics. Variations in mothers' ratings of their infant's temperament are associated not only with concurrent sensitivity to crying but also with response tendencies prior to parenthood. These predispositions appear to affect the development of the infant-mother bond a year later. (Author/RH)