Although childhood aggression and conduct problems receive much clinical and research attention, important variations in function underlying the common syndromes are less often analysed. In this article, we describe a particular pattern of behaviour in young children, which we have occasionally observed in various clinical contexts. The critical feature of this pattern is that the children are described by those who know them well as interpersonally negative, often revealing spiteful, hostile behaviours, particularly towards parents or siblings. The general temperamental pattern is one of irritability, so that the children have a disgruntled, irascible disposition. Although their behaviour can escalate to apparently unprovoked, and sometimes severe, aggressive acts that suggest a lack of feeling towards others, the children have no deficit in empathy. Instead, either their own need for anger reduction is greater than any concern for others, or, being vengeful, they are aware that their actions will be hurtful to others. We make comparisons with the critical features of established clinical syndromes, and speculate as to how the proposed pattern might be a functional explanation for some individual children whose behaviour otherwise fits standard diagnostic classifications. Possible temperamental and family relationships factors are proposed that might contribute to this pattern of hostile mood, particularly parenting practices that could be perceived as unfair by the child.