One's own temptation to misrepresent creates a self-fulfilling logic in which one believes one needs to misrepresent because the other is likely to do it as well
Whenever we perceive a new information, we would look at the information with a pre-existing intellectual frame that we already develop from our past knowledge/experiences. This intellectual frame tend to be really subject, and often cause us to interpret the information in a way that would benefit or reaffirm our own personal bias.