V. K. S. Nayar has said that, "the matrilineal system tends to produce a society at once hierarchical and authoritarian in outlook. The system is built round family pride as well as loyalty to the "karavanar"". Nossiter cites this as one reason why it was "congruent with the role of a military caste in a feudal society." and explains that the decline in the traditional warrior role, the rise of an economy based on money, together with the ending of agricultural slavery and the effects of western education, all combined to cause the decline of the traditional practices. All of these factors were having an impact during the 19th-century and they caused erosion of the social dominance which the Nairs once held, eventually reaching a point some time between World War I and World War II where that dominance was lost, although there was an attempt to reassert it in Travancore during the 1930s when the Diwan Sir C. P. Ramaswamy Iyer adopted a pro-Nair stance and an oppressive attitude towards communities such as the Syrian Christians. The main beneficiaries in the shifting balance of social influence were the Syrian Christians and the Ezhavas. The former, in particular, were in a position to acquire, often by subdivision, the economically unviable "tharavad" buildings and landholdings around the time of the Great Depression. The role of the Nair Service Society in successfully campaigning for continued changes in practices and legislation relating to marriage and inheritance also played its part. This collapse of the rural society facilitated the rise of the socialist and communist political movements in the region.