According to [[Pragmatic Thinking and Learning]], stress kills cognition because it triggers the brain's primitive "fight or flight" mechanism, causing it to shut down advanced thinking resources to focus on immediate survival. The sources highlight several specific ways this happens: **1. R-mode Shutdown** The most critical cognitive failure under stress is the loss of the **R-mode** (the intuitive, creative engine of the brain). - **Time and L-mode:** The brain's linear processing mode (L-mode) handles the concept of time. When you feel time pressure, the L-mode dominates completely. - **The Result:** Because the R-mode cannot function under these conditions, you lose your "search engine," creativity, and ingenuity precisely when you need them most. **2. Physical and Mental Tunnel Vision** Under pressure, the brain enters a state often referred to as **"lizard logic"**. - **Narrowing:** Your vision literally and figuratively narrows. You stop considering options and focus strictly on the immediate threat. - **Resource Conservation:** The brain actively shuts down "extra" resources to prepare for a physical fight or flight response. - **Bad Decisions:** This leads to disastrous choices. In one simulation, managers under pressure made decisions so bad they appeared to have "had lobotomies." **3. The "Pressure Hangover"** The damage outlasts the event itself: a study by Dr. Teresa Amabile found creativity stays depressed for **two days** after the pressure. **4. Ethical Blindness** Stress can even override deep-seated values. In one study, seminary students normally driven to help stepped over a person in distress (an actor) simply because they were told they were late. Deadline pressure prevented them from acting on their values. In short, "trying too hard" guarantees failure: the brain reads the pressure as a crisis and switches off its higher-level problem-solving. ## Source *Source: [[Pragmatic Thinking and Learning]] — Andy Hunt (Pragmatic Bookshelf, 2008)*