This paper describes a multivariate model of early infant competence formulated from variables representing infant-environment transaction including: birthweight, habituation index, personality ratings of infant social orientation and task orientation, ratings of maternal responsiveness to infant distress and social signals, and observational measures of latency of maternal response to infant distress and vocal signals taken in the home. The Bayley Scales of Mental and Motor Development were administered when the infants were 2 1/2 and 6 months old, and multiple linear regression analysis was performed on infant and maternal variables. The sample consisted of 51 first born infants of normal birthweight and free of significant birth defects. Results of this study support transactional developmental perspective where both infant and environmental characteristics are predictors of competence. (Author/MS)