In this paper we argue that moral behaviour is largely situation-specific. Genetic make-up, neurobiological factors, attachment security and rearing experiences have only limited influence on individual differences in moral performance. Moral behaviour does not develop in a linear and cumulative fashion and individual morality is not stable across time and situations. To illustrate our position we present two studies on children's willingness to donate their money to a charity (UNICEF) as a prime example of pro-social behaviour. In two samples of seven-year-old children we found no evidence for a role of attachment, temperament or parenting. Using a twin design we did not find any evidence for a genetic component either. The most striking finding in both studies was that very few children were inclined to donate any money after viewing a promotional UNICEF film about children suffering from poverty. Only after gentle probing by an experimenter were most children willing to donate some of their money. The situation appeared to be a much more powerful determinant of donating behaviour than any other factor. These findings are discussed in the broader context of evidence for situational canalisation of moral behaviour. We conclude that moral competence may be a universal human characteristic, but that it takes a situation with specific demand-characteristics to translate this "competence" into actual prosocial "performance". (Contains 1 table, 2 figures, and 1 note.)