As humans, we start developing self-awareness at an early stage, usually being able to pass the "mirror test" by our second birthday: the forehead of the baby is dabbed with a spot of odorless dye and the child is set before a mirror. Most animals reach for the mirror in order to touch the spot, but even as babies we are capable of realizing that the spot is on our own body and reach up to touch our own forehead.
The truly interesting thing about self-awareness though is the fact that we rarely notice our self in a neutral way. In the 1970s, social scientists studying the matter observed that people regularly changed their behavior when placed in front of a mirror. According to Roy F. Baumeister and John Tierney, authors of Willpower. Why Self-Control is the Secret to Success, here's what happened:
"Whenever people focused on themselves, they seemed to compare what they saw with some sort of idea of what they should be like. A person who looked in the mirror usually didn't stop at, Oh, that's me. Rather, the person was more likely to think, My hair is a mess, or This shirt looks good on me, or I should remember to stand up straight, or, inevitably, Have I gained weight? Self-awareness always seemed to involve comparing the self to these ideas of what one might, or should, or could, be." (p. 112)A number of related experiments since then have shown that self-awareness helps self-regulation and self-control. Or put another way: when confronted with themselves (i.e. seeing yourself in a mirror), people tend to make better choices. But once you start monitoring your own behavior in order to exercise more self-control, you stumble upon another vital question: Should I focus on how far I've already come or on how much remains to be done? According to Baumeister and Tierney that all depends on how you'd like to feel about yourself: "For contentment, apparently, it pays to look at how far you've come. To stoke motivation and ambition, focus instead on the road ahead." (p. 120)
And if self-monitoring isn't enough to get you to exercise more self-control and finally start losing those extra pounds (just an example, not saying you're fat...honestly), there's one more thing you might want to try -- telling other people about it: "Public information has more impact than private information. People care more about what other people know about them than about what they know about themselves." (p. 121) This is probably the toughest step to take, especially if your bad habit or lack of willpower in a certain area is embarrassing to you. But you know what they say: desperate times call for desperate measures...