MATHEMATICAL-MODELS FOR COORDINATED INTERPERSONAL TIMING IN MOTHER-INFANT INTERACTIONS IN THE FIRST YEAR OF LIFE

Two mathematical models of social contingency are examined in terms of their development over the first year of life. The interactions of 53 mothers and their infants were recorded at 6 weeks, 4 months, and 12 months. The infants' gazes at 6 weeks, the mothers' vocal behavior at 6 weeks: and the vocal behavior of the mother and infant at 4 and 12 m onths were automatically coded in terms of four states. The conditiona l dependence model and the response effects model were computed for ea ch interaction at each age, and the coefficients of the models were ex amined as a function of age. The relative success of the models as est imates of moment-to-moment contingency as well as their variations wit h age are discussed.