Twelve psychological findings that have real evidence behind them and direct productivity implications. Each gets a one-line mechanism and a one-line application — no filler.

1. The Zeigarnik effect

Unfinished tasks occupy memory more than completed ones. Application: write down unfinished tasks at day's end so they stop renting your attention overnight.

2. Implementation intentions

"If X happens, I will do Y" statements dramatically improve follow-through versus vague goals. Application: pre-commit to when and where for every important task.

3. Ego depletion (partial)

Self-control is partly a finite resource within a day. Application: front-load demanding decisions to morning hours when reserves are fullest.

4. The fresh-start effect

Milestones — new week, month, birthday — make behaviour change more likely. Application: start new habits on dates that mean something, not arbitrary Wednesdays.

5. Temptation bundling

Pair a want-to with a should-to (podcast + gym, favourite show + folding laundry). Application: engineer the pair explicitly.

6. The planning fallacy

We systematically underestimate task duration. Application: multiply estimates by 1.5-2× for better honesty.

7. Parkinson's law

Work expands to fill the time allotted. Application: give yourself tighter windows on purpose.

8. Loss aversion

Losses feel roughly twice as costly as equivalent gains. Application: frame habit changes as avoiding loss ("I'm going to lose another year if") rather than securing gain.

9. Default bias

People stick with whatever the default is. Application: set defaults — auto-enrolled habits, auto-scheduled weekly reviews, pre-set focus mode at 9 AM — so willpower isn't the gatekeeper.

10. The spacing effect

Distributed practice beats massed practice for retention. Application: review material across days rather than cramming; applies to both learning and long-running projects.

11. The IKEA effect

We value what we build ourselves. Application: build your own templates, routines, and checklists; the adherence is notably higher.

12. Social commitment devices

Publicly stating goals increases follow-through. Application: one weekly public goal. Accountability partner, Slack channel, or blog — pick whichever sticks.

Don't try all twelve. Pick two that match something you're struggling with and treat them as experiments for two weeks.