A chain of innovation is social network , defined by offering or adopting and economic innovation. The main hypothesis is that diffusion of rural innovations and the changes of life-style of the peasants (generally: the growth of market economy) do not necessarily restructure or destroy local networks, but in some case they will be reinforced. There are two different forms of economic behaviour: that of the innovator and of the model imitator. The innovator is an enterpreneur in Schumpeter's sense: an economic actor implementing innovation. Other entrepreneurs do not innovate so they copy the existing economic models. The members of peasant societies are mostly model imitators. This economic behaviour is based on peasant social networks: prestigious people are also recognised as economic examples to be followed, so their innovations will be accepted. On the other hand, the strongly tied rural actors, who worked mostly together and represented many times their relatonships with all due solemnity, are socially urged to help their smaller relations even with economic advice. If the example is to be the entrepreneur, many connected households will be also entrepreneurs - but not necessaily innovators. There will be new technologies adapted in the community; even life-style will chenge, but not the social networks that present major stability. To illustrate this hypothesis there is the description of two cases of anthropological fieldwork conducted in rural areas. One is the example of an indigenous community of the Peruvian Andes and the other one is of a Hungarian village.