Are upper-class individuals more inclined to violate rules? Using behavioural data, recent studies have challenged the traditional assumption of upper social class members being less rule violating, while other studies find no or opposite effects. We bring together behavioural decision-making games with traditional survey measures in a unique setup to re-evaluate the proposed relation between social class and rule violations, distinguishing between the economic and the psychological components of social class. Drawing from a cohort of 750 Swiss adults, we investigate how the conditions they were born in (social origins) and the current financial resources (disposable income) affect self-reported and behaviourally measured rule violations in the lab. Interestingly, our findings show that disposable income impacts the behaviour of individuals conditional upon their social origins. For people with upper social origins an increase in disposable income leads to more rule violations than for people with lower social origins. Additional analyses show that a similar pattern emerges when analysing the different perceptions of morality that the two groups have. We conclude that with increasing disposable income, people with upper social origins become more morally flexible, as they are more tolerant of rule violations and violate the rules more often than individuals with lower social origins.