An ordinal pattern analysis of four hypotheses describing the interactions between drug-addicted, chronically disadvantaged, and middle-class mother-infant dyads.

This study investigated mother-infant interactions in 18 dyads. All participants were African American and enrolled in an early intervention program because the infants (2-26 months of age) had developmental disabilities or were at high risk for developmental disability. Some mothers had used drugs during their pregnancy, and all mothers were of low or middle socioeconomic status. Dyads were videotaped interacting at 4 different times, separated by at least 5 months in time. Videotapes were rated in terms of infant involvement and maternal responsivity in the interaction. 4 hypotheses concerning the pattern of maternal interaction across time were tested using ordinal pattern analysis. The hypothesis that mothers would become less responsive to infants over time (HD) as a function of drug addiction, poverty, or serious developmental delay was supported for only 4 of the 18 dyads. There was support for the hypothesis (H(I)) that mothers naturally increase their responsivity over time (N = 6) and support for the hypothesis (HT) that mothers' interactive sensitivity fluctuates in relation to infants' involvement in the interaction over time (N = 7). Ordinal pattern analysis has advantages in determining how well competing hypotheses describe individuals within populations relative to approaches that identify differences that apply to entire populations.