Human beings are not always—in fact, probably not often—the objective, rational creatures they like to think they are. In the past few decades, psychologists have demonstrated the many ways people deceive themselves every step of the way through the process of reasoning. Indeed, cognitive faculties are a distinguishing feature of humanity—lifting humankind out of caves and enabling the arts and sciences—nevertheless, they are also rooted in and subject to influence, or bias, by emotions and deeply ingrained instincts. One of the most significant ways information processing and decision-making becomes warped is through motivated reasoning, the bias toward a decision that conforms to what a person already knows, and it occurs outside of awareness that anything sneaky is going on.
Cognitive scientists see motivated reasoning as a force that operates in many domains. Studies by political psychologists highlight denial of global warming or discrediting its science as important examples of motivated reasoning; people process scientific information about climate shifts to conform to pre-existing feelings and beliefs. After all, accepting that climate change is real portends unpleasant environmental consequences and would require most people to head them off by making significant changes in lifestyle. Changing one’s mind and changing one’s lifestyle are hard work; people prefer mental shortcuts—in this case, having the goal fit their ready-made conclusions.