Burkina Faso is currently facing a serious deterioration of water quality due to the use of pesticides in agriculture, which is an even greater challenge for the government since farmers are unaware of the toxicity of these chemicals. Therefore, reducing pesticide use requires updating farmers' beliefs about the environmental and health consequences of their actions. Drawing on the theory of positional objectivism developed by Sen, this study seeks to determine the influence of various positional characteristics (gender, education level, socio-cultural factors, etc.) on individual beliefs. In so doing, it uses a recursive bivariate probit model. The model was tested using data collected from a sample of 389 farmers. The results from this model showed that the more farmers' had beliefs about the degradation of water quality, the less they were inclined to use pesticides. These beliefs were based on personal lived experiences and were also formed through interactions with other farmers. Moreover, government agencies and NGOs in regular contact with the farmers played a crucial role in shifting the farmers' observational positions.