Fourteen findings from happiness research that are robust enough to rely on and useful enough to apply.

1. Hedonic adaptation is real — you return to baseline happiness after big events within months.
2. Relationships matter most — the #1 predictor of long-run happiness in the Harvard Adult Study.
3. Gratitude with specificity changes mood measurably; vague gratitude doesn't.
4. Experiences produce more sustained happiness than material purchases.
5. Giving produces more happiness per dollar than spending on yourself.
6. Flow states — absorbed work — are the highest measurable happiness states.
7. Sleep deprivation drops happiness faster than almost anything else.
8. Exercise is antidepressant — effect sizes comparable to medication for mild-to-moderate cases.
9. Nature exposure lifts mood; 20 minutes weekly has measurable effects.
10. Social comparison erodes happiness; curate your reference group deliberately.
11. Meaning matters as much as moment-to-moment happiness — the two are separable.
12. Negativity bias is real — unhappy events get more mental weight than happy ones unless deliberately corrected.
13. Ageing tends to increase happiness in most populations — contrary to popular belief.
14. Helping others activates the same brain regions as receiving help — service isn't just virtuous, it's pleasurable.

Fourteen facts; apply three. Happiness isn't a discovery project; it's a practice informed by evidence.