This term was popularised by the titles of three volumes from a seminal 1960s British project led by John Goldthorpe and David The study of affluent manual workers in the British car industry was intended to test the embourgeoismen: (or becoming middle class) thesis Marxist theories suppose the working class is defined by its lack of ownership of the means of production (and hence lack of power). The embourgeoistment alternative is that attitudes and behaviour are influenced more by wealth than by ownership and control; as workers become better paid they will become more like the middle classes. The Affluent Worker studies came to importantly different conclusions. These workers had become more like the middle class in some respects (e.g. buying their own houses and favouring domestic over community leisure activities) but they continued to vote for the Labour party and remained active in trade unions. In these activities, rational self-interest was more important than traditional community loyalties; ‘instrumental collectivism’ had replaced class solidarity.