When an intuitive answer to a problem feels slightly off, the human brain generates an uncomfortable state known as doubt. This negative feeling acts as an internal alarm bell that prompts individuals to abandon simple mental shortcuts and engage in heavy, analytical thinking. The new findings detailing this emotional trigger were published in Thinking & Reasoning. Psychologists often categorize human thought into two distinct cognitive systems. The first system is intuition, which provides rapid, effortless, and almost automatic responses to everyday situations. This system operates so quickly that we are rarely aware of its mechanics. The second system is deliberation, which requires deep logical analysis, conscious effort, and consumes a massive amount of mental energy. Because deliberation is so energetically expensive to maintain, humans naturally prefer to rely on their intuition whenever it appears adequate for the task at hand. A major question in cognitive psychology is how the brain knows when to switch from easy intuition to taxing deliberation. Many existing psychological models suggest this cognitive switch happens through a quiet metacognitive evaluation. Metacognition …