psychology-foundations

# Psychology Foundations

Understanding *why* patterns work lets you apply them to new situations. These are the research foundations beneath UX practice.

## About This Skill

This skill contains **research-backed principles only**. Each concept includes:
- The original researcher(s)
- Year of key publication(s)
- What the research actually showed
- Limitations or caveats where relevant

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## 1. Dopamine and Anticipation

**Researchers:** Wolfram Schultz (1990s), Robert Sapolsky
**Field:** Neuroscience

### What Research Shows

Dopamine neurons fire in response to **prediction of reward**, not reward itself. When a reward is expected and received, dopamine levels don't spike at reward time—they spike at the cue predicting the reward.

Schultz's experiments with monkeys showed:
- Unexpected reward → dopamine spike at reward
- Expected reward (after learning) → dopamine spike at predictor, not reward
- Expected reward that doesn't come → dopamine dip (disappointment)

### UX Implication

Progress indicators work because they signal approaching reward. The anticipation phase is neurologically active.

**Source:** Schultz, W. (1998). Predictive reward signal of dopamine neurons. *Journal of Neurophysiology*.

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## 2. Peak-End Rule

**Researchers:** Daniel Kahneman, Barbara Fredrickson
**Field:** Behavioral economics, Psychology
**Recognition:** Nobel Prize in Economics (2002)

### What Research Shows

In studies of colonoscopies and other experiences, participants rated overall experience based on:
1. The **peak** moment (most intense)
2. The **end** moment

Duration had little effect ("duration neglect"). A longer painful experience ending gently was rated better than a shorter one ending abruptly.

### UX Implication

- Create one memorable positive peak
- End interactions well
- A graceful error recovery can redeem a frustrating experience

**Source:** Kahneman, D. et al. (1993). When more pain is preferred to less. *Psychological Science*.

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## 3. Loss Av