The Pennsylvania Infant and Family Development Project, I: Stability and change in mother-infant and father-infant interaction in a family setting at one, three, and nine months.

In order to further understanding of the development of the father-infant relationship, patterns of mothering and fathering in 72 families were observed longitudinally (at 1, 3, and 9 months) and from the perspective of the family system. Analyses of variance revealed comparable developmental change in maternal and paternal behaviors, but striking differences between parents, with mothers engaging in far more interaction at all ages studied. Analyses of individual differences in maternal and paternal behavior revealed consistent stability over time, especially from 3 to 9 months, thereby highlighting points of similarity in mothering and fathering. Within-age correlational analyses revealed consistent positive associations between measures of father-infant and husband-wife interaction, yet little relationship between measures of mother-infant and spousal interaction. These findings and others are discussed in terms of similarities and differences in mothering and fathering.