The problem with precision, though, is that it can often be discouraging. Let’s say you want to lose 10 pounds. After following a strict diet for a few days, you then decide to weigh yourself. The good news is that you have lost weight. The bad news is that you’ve only lost 4 pounds. While that represents progress, it probably feels pretty disappointing, since you’ve already worked hard and you’re not even half way to the goal. As a result, you might become a little less motivated, which means that you start to cheat on your diet. Before long, those pounds are back – you’ve been undermined by the precise feedback. The larger point is that the exactitude of the scale made it impossible to ignore the lack of success, which makes us more likely to surrender. And this is where vagueness comes in: when information is ambiguous we typically settle on more generous interpretations – Perhaps we’ve lost eight pounds! Perhaps we’re just retaining water! – which means that we stay motivated. In this sense, vagueness is a useful delusion, a nifty means of remaining committed to long-term goals. Reality is a deterrence.
Hang on — is it true that "when information is ambiguous we typically settle on more generous interpretations"? And is it true that "generous interpretations" mean that we "stay motivated"? I'm not sure I buy either of those completely unsupported assertions.
Let's suppose that I do interpret generously: if all I know is that I've lost some weight but less than ten pounds of it, what's to keep me from saying, "Hey, maybe I've lost eight or nine pounds, in which case this milkshake won't set me back too far"? Why makes that assumption less likely that "I'm probably nearly at 10 pounds so I'll push harder to get there"?