While previous research has shown that social preferences develop in childhood, we study whether this development is accompanied by reduced use of deception when lies would harm others, and increased use of deception to benefit others. In a sample of children aged between 7 and 14, we find strong aversion to lying at all ages. Lying is driven mainly by selfish motives and envy. Children with stronger social preferences are less prone to deception, even when lying would benefit others at no monetary cost. Older children lie less than younger children and require more selfjustification to lie.