Perceptive Expectations
Perception is an active process where stimuli observed by receptor organs are influenced by past experience, education, cultural values, and role requirements. Information obtained depends upon the observer's assumptions and preconceptions, and by the context where different circumstances evoke different sets of expectations. There is a strong tendency in human perception to model perception according to expectation, humans tend to perceive what they expect to perceive.
It takes more information and data processing, to recognize an unexpected phenomenon than an expected one. Expectations have diverse sources, including past experience, education, professional training, and cultural and organizational norms. This tendency to perceive what is expected seems much more important than any tendency to a desired perception or so called wishful thinking.
Trying to be objective does not ensure accurate perception and patterns of expectation can become so deeply embedded that they continue to influence perceptions even after a wrong preconception has been corrected. Expectations form a set of Mind Patterns, a predisposition to think in certain ways, like a menu through which one interacts with the world. Patterns of expectation are placing relevance in modes of interpretation. The idea of being influenced only by the facts rather than by preconceived notions is naive for there is no such thing as "facts". There is only a very selective subset of an overall mass of data. Being subjected to this subset allows one to classify and judge the relevance to the question at issue.