A model of caregiver-child interaction processes is proposed in which adult attributions are conceptualized as moderator variables. Adult attributions are seen as acting in either a sensitizing or a buffering role in determining the extent to which child behavior or characteristics influence adult affect and behavior. In earlier research (Bugental and Shennum, 1984), this model was tested in a laboratory analog of family interaction. Support was found for the model in terms of nonverbal manifestations of affect. Research reported here extends those findings by exploring the physiological function of child characteristics and caregiver attributions. Eighty undergraduate women viewed videotapes of responsive and unresponsive children in anticipation of interacting with them later. All subjects were premeasured on the Parent Attribution Test (PAT). During viewing and post-questioning, continuous readings were made of their heart rate, skin temperature, and skin conductance. Subjects with low perceived control (PC) over caregiving outcomes, as assessed by the PAT, were found to be more reactive to child responsiveness or unresponsiveness than subjects with high PC. Low PC subjects reacted to unresponsive children with decreased levels of skin temperature and increased heart rate and skin conductance, suggesting anxious arousal. The model is also applied to ongoing research on families at risk for child abuse. (RH)