Key Words: emotional transmission, family process, one-parent families, parent-adolescent relationships. This study examines the paths of emotional transmission in one-parent, mother-headed families. One hundred adolescents and their single mothers provided self-reports of their immediate experience at random times when signaled by alarm watches over I week. Time sequence analyses indicated that mothers' immediate anxiety and anger were related to subsequent anxiety and anger in adolescents, but adolescents' negative emotions were not related to subsequent negative emotions in their mothers. The transmission of anxiety to adolescents was most evident in families in which mothers had more stress and employed psychological control in their parenting. It was least evident in families in which mothers spent more time alone. These ,findings suggest daily processes whereby distress is propagated in some families and contained in others. Families are emotional systems in which strong feelings experienced by one family member may be dealt with and subdued or may be propagated by being transmitted to other family members. Knowledge of the paths of emotional transmission in families is important for understanding how stress and distress in one member's life enters the family system and affects the well-being of other members (Larson & Almeida, 1999). Longitudinal studies have documented that depression or other forms of maladjustment in one family member, particularly a parent, leads to maladjustment in others (Conger, Patterson, & Ge, 1995; Downey & Coyne, 1990; Easterbrooks & Emde, 1988; Grych & Fincham, 1990; McLoyd, 1989; Patterson & Dishion, 1988). However, we have little direct information about the daily processes whereby this maladjustment is conveyed among family members, nor do we know what occurs in some families that prevents it from being conveyed. Repeated daily occurrence of emotional transmission may be the immediate mechanism responsible for creating and sustaining these long-term effects. Diary and time-sampling research suggests that in two-parent families emotions tend to flow from the father and husband to other family members (Bolger, DeLongis, Kessler, & Wethington, 1989), a path of transmission that may reflect the adult male's position of power (Larson & Richards, 1994a). For one-parent, mother-headed familieswith no father in the home-two contrasting hypotheses could be proposed. Some have argued that relationships between single mothers and their children, particularly adolescent children, are more peer-like, that the parent is less dominant than parents in two-parent families (Demo, 1992; Glenwick & Mowrey, 1986; Weiss, 1979). This might suggest symmetry in paths of transmission-that single parents and adolescents are equally likely to transmit emotions to each other. An alternate hypothesis is suggested by a theoretical perspective that sees the well-being of children in one-parent families to be especially sensitive to the stress and well-being of the parent (Amato, 1993; Simons & Associates, 1996). This perspective leads to the prediction that emotions in the lives of single parents may have more effect on children's, even adolescents', emotions than the reverse. To examine these competing predictions, this study employs data from the immediate daily lives of single mothers and their adolescent children. We evaluate whether emotions are transmitted bidirectionally between parent and adolescent or unidirectionally from mother to adolescent. In addition, we examine the sources of emotions that are transmitted and evaluate moderators of this transmission. BACKGROUND Emotional Transmission in Two-Parent Families Prior research on daily emotional transmission in families has dealt almost entirely with couples and two-parent families. Nonetheless, it is a useful starting point for thinking about the emotional dynamics of one-parent families. …