Stability of mother-infant interaction from 6 to 12 months

The stability of ten measures of mother-infant interaction covering six dimensions of mother-infant relationships was examined from age 6 to 12 months. The measures were based on two hours of naturalistic observation, using videotape, in the home at each of four age points (twice in the 6th month and at 9 and 12 months). The study was an intensive investigation of a small sample (four normal mother-infant pairs). Substantial stability of individual differences, in the sense of pairs repeatedly scoring above or below the sample mean, was found in 7 of 10 measures. The stability found covered aspects of mother-infant relationships open to deliberate control and management as well as aspects dealing with more spontaneous and uncontrolled styles of relating. Three measures showed distinct age trends, suggesting that aspects of "caregiving" changed during the six months. Two measures showing pronounced age changes nevertheless revealed individual difference stability.