At each of the three assessments, parents were asked to interact with their children as they normally would at home for 10 min in a room filled with toys. Mother–child and father–child interactions were conducted separately. At the 12 and 24 month assessments, the free-play interactions were coded using a collection of global five-point rating scales developed by Clark, Musick, Scott, and Klehr (1980). These scales have been found to be applicable for children ranging in age from 2 months to 5 years (Clark, 1999; Clark et al., 1980). Composite measures of maternal and paternal warmth/sensitivity were derived from these scales, yielding two composite scales, one for mothers and one for fathers at each age. The warmth/sensitivity composite included items such as expressed positive affect, positive involvement, responsiveness, reading child cues, flexibility, low intrusiveness, and consistency/predictability. Higher scores on these scales indicated high warmth/sensitivity. The internal consistency (Cronbach's alpha) for these composite scales ranged from .90 to .93 for mothers' warmth/sensitivity and .90 to .95 for father's warmth/sensitivity at the 12 and 24 month assessments respectively.
