Earlier, in Bihar, in 1811-12, Botanist and Zoologist, Francis Buchanan had recorded the Kayastha of that region as "pure shudra" and accordingly kept them at the par with other producer caste groups like goldsmiths, Ahirs, Kurmis and the Koeris. William Pinch, in his study of Ramanandi Sampradaya in the north describes the emergence of the concept of "pure Shudra" in growing need of physical contact with some of the low caste groups who were producer and seller of essential commodities or were the provider of services without which the self sufficiency of rural society couldn't persist. However, many of these adopted Vaishnavism in the aim to become Kshatriya. In 1901 Bihar census, Kayasthas of the area were classified along with Brahmins and Rajputs in Bihar as “other castes of twice-born rank” According to Arun Sinha, there was a strong current since the end of the 19th century among Shudras of Bihar to change their status in caste hierarchy and break the monopoly of bipolar elite of Brahmins and Rajputs of having "dvija" status. The education and economic advancement made by some of the former Shudra castes enabled them to seek the higher prestige and "varna" status. The Kayastha along with the Bhumihars were first among the shudras to attain the recognition as "upper caste" leaving the other aspirational castes to aspire for the same.