principle

• Delayed gratificationprinciple

  The ability to give up a small, immediate reward for a larger one that comes later. Research shows that it depends a lot on where you keep your attention and on how much you trust that the promised reward will actually come.

• Ego depletionprinciple

  The idea that willpower is a limited resource, used up by every act of self-control, was one of the most cited in psychology. Large preregistered replications no longer found the effect in the lab. Fatigue is real, but the "willpower tank" remains an unsupported hypothesis.

• Habit formationprinciple

  A habit forms by repeating the same behaviour in the same context until it becomes automatic. It doesn't take 21 days, as people say: in studies, the median was about two months, with very large differences from person to person.

• Pareto principleprinciple

  In many fields, a few causes produce most of the effect. This concentration is real and measurable, but the exact ratio varies a lot from case to case. "80/20" is an easy-to-remember formula, not a law.

• Planning fallacyprinciple

  People usually underestimate how long their own projects will take, even when they know that similar projects ran late. It helps to start from how long similar cases took, not from your plan.

• Sunk costprinciple

  Money, time or effort already spent won't come back, whatever you decide now. Still, people tend to keep going with something just because they have already invested in it. It helps to judge each decision by what comes next, not by what has been spent.