Brocas and Carrillo propose a model to make decisions based on noisy sensory inputs, beliefs about the state of the world are modified by Bayesian updating, and then decisions are made based on beliefs passing a threshold. They show that this model, when optimized for single-step decision making, produces belief anchoring and polarization of opinions – exactly as described in the global warming controversy context – in spite of identical evidence presented, the pre-existing beliefs (or evidence presented first) has an overwhelming effect on the beliefs formed. In addition, the preferences of the agent (the particular rewards that they value) also cause the beliefs formed to change – this explains the biased assimilation (also known as confirmation bias) shown above. This model allows the production of controversy to be seen as a consequence of a decision maker optimized for single-step decision making, rather than as a result of limited reasoning in the bounded rationality of Daniel Kahneman.