Background: Confirmation bias is the tendency to acquire or evaluate new
information in a way that is consistent with one's preexisting beliefs. It is
omnipresent in psychology, economics, and even scientific practices. Prior
theoretical research of this phenomenon has mainly focused on its economic
implications possibly missing its potential connections with broader notions of
cognitive science. Methodology/Principal Findings: We formulate a
(non-Bayesian) model for revising subjective probabilistic opinion of a
confirmationally-biased agent in the light of a persuasive opinion. The
revision rule ensures that the agent does not react to persuasion that is
either far from his current opinion or coincides with it. We demonstrate that
the model accounts for the basic phenomenology of the social judgment theory,
and allows to study various phenomena such as cognitive dissonance and
boomerang effect. The model also displays the order of presentation effect|when
consecutively exposed to two opinions, the preference is given to the last
opinion (recency) or the first opinion (primacy)|and relates recency to
confirmation bias. Finally, we study the model in the case of repeated
persuasion and analyze its convergence properties. Conclusions: The standard
Bayesian approach to probabilistic opinion revision is inadequate for
describing the observed phenomenology of persuasion process. The simple
non-Bayesian model proposed here does agree with this phenomenology and is
capable of reproducing a spectrum of effects observed in psychology:
primacy-recency phenomenon, boomerang effect and cognitive dissonance. We point
out several limitations of the model that should motivate its future
development.

该研究通过非贝叶斯模型描述了确认偏误和透视误导之间的关系，并验证了其基本现象学和学习特性，并探究了它们在认知心理学中的实际应用。