Fifty-five 4-year-old children took part in a study focused on children's accounts of the situations that caused happiness, anger, sadness and fear in themselves, their friends, and their mothers. Themes, agents, and adequacy of accounts were studied at two time points. Interpersonal causes of anger and happiness were cited by many children; confusion about causes of anger and sadness was not evident, although the notion of loss and controllability as factors distinguishing causes of anger versus sadness found some support. Accounts (...) for self, friend, and mother differed considerably, suggesting emotion understanding could usefully be considered in relation to specific relationships. Analysis of individual differences showed that children who scored high on deception, emotion understanding, and false belief tasks at 47 months gave more adequate and differentiated accounts of mothers' and friends' emotions seven months later. Implications for our views of children's close relationships are discussed. (shrink)