DiLalla, L.F., Wingo, A., & Bishop, E G (1994). Differential mother-child interactions in infancy and their effects on infant vocalizations. Poster presented to the American Psychological Society Conference, June, Washington, D.C.

The goal of this study was to increase our understanding of the mechanisms involved in differential parent/child interactions. Previous studies have examined parental interactions with siblings of different ages, comparing them only at the same age or at the same point in time. This project included twin siblings, thus controlling for sibling age differences as well as life event effects on parental behavior. This study examined: 1) the heritability of infant vocalizations; and 2) differential maternal treatment as it impacted on infant vocalizations. Results showed that infant vocalizations were more heritable at 9 months than at 7 months. Also, mothers responded more similarly to identical twins than to fraternal twins when acknowledging infant vocalization behaviors, suggesting that genetically identical infants elicited more similar environments, although this did not hold for all maternal variables.