According to studies, our brain uses 2 modes of reasoning when it comes to decision making:
1. Heuristic (intuitive, automatic, implicit processing)
2. Analytic (deliberate, rule-based, reasoning, explicit processing)
A heuristic is a mental shortcut, automatic and intuitive way of making decisions, which often dominates our decision making and problem solving in creative, fast and easy decisions and situations. For the most part, heuristics are helpful, because they allow us to quickly make sense of a complex environment, but there are times when they fail at making a correct assessment of different situations or problems. So, the problem of heuristics is that it sometimes results to biased solutions - but “good enough” for a given set of goals.
Hence, biases arise from the use of the heuristic. When our heuristics fail to produce a correct judgment, it can sometimes result in a cognitive bias, which is the tendency to draw an incorrect conclusion in a certain circumstance based on cognitive factors.
Cognitive bias is the tendency to make decisions or take action in an illogical way. For example, you might subconsciously make selective use of data, or you might feel pressured to make a decision by powerful colleagues. We can see cognitive bias as the opposite of common sense and clear, measured judgment. Bias can lead us to poor decisions and missed opportunities.