Biases fall into two general categories: our biases and the biases of others. Biases in our actions or perception tend to occur unconsciously. It is interesting to note that people tend to believe that their own perceptions reflect reality, and if others tend to see things differently (disagree with our position or thinking), then they must be biased.
This results in the tendency of people to deny their own biases while recognizing biases in others, which leads to a serious deficiency in self-awareness and, to some degree, impacts our interaction with others.
We have one brain but two minds. One mind makes conscious choices based on careful consideration, self-reflection, insight, and observation—the mind of self-control.
The other mind makes automatic choices based on past experience, habit, and/or instinct—the mind of impulse and habit. Neuroscientists propose that these two "minds" are supported by different neural circuits that activate thoughts, behaviors, and emotions.
Stress or pressure plays a role in activating the automatic neural circuitry while suppressing the conscious circuitry, thus making biases unconscious.