Mother-infant interaction characteristics at six ages during the first year of life were studied in relationship to the development of the infant's fear of strangers (FOS) during the first year. Among 46 offspring of women with psychosis history, a failure to develop the expected FOS was associated with antecedent negative qualitative aspects of interaction such as increased maternal tension, reduced harmony in feeding and increased infant crying. Among 80 low-risk control infants, a failure to develop FOS was associated with an antecedent quantitative reduction in social contact within the mother-infant pair. At a case level, an absence of FOS overlapped little with anxious attachment to the mother, and these two developmental phenomena bear partially different relationships to the mother-infant interaction characteristics.

Mother-infant interaction characteristics at six ages during the first year of life were studied in relationship to the development of the infant's anxious vs. secure attachment to the mother at 1 year of age. The same antecedent maternal characteristics, notably less harmony during feeding and less consideration for the child's needs in play, were associated with anxious attachment in both index and control groups. In contrast, control infants' behaviors were totally unrelated to the development of anxious attachment, while index infants developing anxious attachment evidenced reduced social contact toward the mother and increased crying prior to 1 year, suggesting either vulnerability to negative maternal influence or initial deviations in these index offspring.

Among the offspring of 88 pregnant index women with a history of nonorganic psychosis, offspring whose mothers developed postpartum psychotic episodes (PPPs) following birth (maximum n = 17) were compared with the remaining index offspring on emotional development during the first year of life, temperament characteristics during the first 2 years, and mental characteristics at 6 years of age. The maternal PPPs were not associated with any negative consequences for offspring development, and the offspring of PPP cases evidenced a number of more positive mental developmental characteristics than did other index offspring. Further comparison with offspring of normal-risk controls also supported the conclusion of no negative effect caused by maternal PPPs. Choice of an appropriate comparison group for PPP cases is discussed.