The simple answer to this question is—it’s how we are wired. Let consider two facets of our brain’s function. The first facet is the reflective system, whose key function is devoted to controlled processing. The reflective system governs conscious, explicit processes. Motivation and effort are required to engage this part of the brain, and the brain in turn requires sufficient time to process content.
The second facet is the reflexive system. This facet of the brain is devoted to automatic processing. The reflexive system is often unconscious or implicit, requires little effort, and operates quickly. Consider the circumstance in which the reflective system interprets stimuli one way, whereas the reflexive system interprets the same stimuli a different way. One’s cognitive, conscious values assert “fair treatment for all,” whereas the unconscious response may be to “protect self from harm.”6 Further exploration of the processing and the interaction between the reflective and reflexive systems provides additional insight into the question: How can well-meaning people have bias?