The social axioms system uniquely predicted a large variety of behaviours and preferences. It is suggested that (a) the assistance social axioms provide in predicting the behaviour of others, and (b) the self-characteristics embedded in the axioms account for this unique prediction ability. Three studies, each pertaining to a different axiom, tested the prediction power of the social axiom regarding two types of behaviours: One that is directly impacted by how others are expected to behave, and another that is more self-directed. Results consistently revealed a unique contribution of the social axioms over personal characteristics in prediction of behaviours directed by how others are expected to behave, whereas behaviours that are more self-directed were largely explained by relevant personal characteristics. Copyright © 2010 John Wiley & Sons, Ltd.