Previous research has demonstrated that value-congruent behaviour is increased after people have considered reasons for or against the value (since values typically lack cognitive support). The present research importantly extends these previous findings. Specifically, based on the reasoning that values can be categorised into different motivational types, it was predicted that considering reasons (i.e. providing cognitive support) for or against a specific value should increase behaviour that expresses a related value. Two studies provided strong support for this central prediction. In Study 1, participants who were asked to consider reasons for or against the values of honesty and loyalty were especially likely to engage in helping behaviour. In Study 2, participants who considered reasons for the value of helpfulness were especially likely to behave in an egalitarian manner (compared to participants who did not consider reasons, and participants who were merely primed with helpfulness). The implications of these findings for when and why considering reasons for a value influences value-expressive behaviour, as well as some practical implications, are discussed. Copyright © 2006 John Wiley & Sons, Ltd.