In Chapter 3, data was presented which showed clear differences between the social beliefs of individuals involved to varying extents in collective action in trade union and gender contexts. Clear differences emerged relating to social identity, relative deprivation, collectivist orientation, political efficacy and the perceived costs and benefits associated with participation. Having established these differences, the next step concerns the causal connections - to what extent are these beliefs causes or effects of involvement? The present chapter will focus on reasons for initial involvement and will make use of qualitative data concerning involvement in women’s groups which illustrates and develops the themes discussed in Chapter 3.