First of all - like fish and chips - self-esteem and confidence are related but quite different concepts. Self-esteem involves some kind of measurement, from the Latin aestimare meaning ‘estimate’. It involves a self-assessment - the measurement of our own self-worth.
Confidence also involves a measurement, it's an assessment of how well we (or someone else) can be relied upon to behave in a particular way or perform a certain task. So, I'm fairly confident that I can finish writing this blog, but I'm not confident that anyone will read it!
So what is the relationship between self-esteem and confidence? I can't answer this question fully. You would think that people with high self-esteem would also have high levels of self-confidence; but there are many people, some pop stars for example, who have very low self-esteem but are confident enough to get on stage and entertain thousands of people. Maybe this kind of incongruence is unsustainable, so eventually the whole façade comes crashing down. It seems to me that self-esteem is the foundation on which self-confidence is built and without firm foundations confidence can be pretty shaky. In contrast, if someone is confident about performing well at some task and they perform badly, then that can be generalised to, “I didn’t perform well, I am a loser”. It's an interesting interaction.
I think it is completely rational to have low self-esteem, especially in an unsafe environment like an abusive relationship or family. Low self-esteem has to be maintained just as much as high self-esteem, it's just that the maintenance of low self-esteem has become so automatic and effortless that we do it without thinking. Low self-esteem makes sense because it keeps us safe and prevents us from taking risks. Feeling we are not good enough to go for a new job justifies not applying and saves all the anxiety of going for the interview or the possible rejection of missing out. Low self-esteem keeps us safe, but at a huge cost because people with low self-esteem can miss out on the good stuff and on reaching their full potential.
Feed Your Self-esteem
On the groups I co-facilitate I try to help group members uncover the strategies they have for maintaining low self-esteem. For example, individuals develop ingenious ways of discounting compliments from others. Once that is exposed, an individual can choose healthier ways to handle positive feedback. I invite group members to list some ways they can "feed" their self-esteem, treats that cost nothing but make them feel good: having a hot bath, going for a walk, feeding the birds or writing a blog entry! It's our attitude that's important. Having a luxurious bath with candles and aromatherapy oils feeds our self-esteem much more than "a quick bath then we don't stink in the morning".
The final thing I ask group members to do to improve their self-esteem is to keep a diary for one week. I ask them to write in their diary each night three positive things that have happened to them during that day. At the next session they can read out their diary entries and re-live the positive things that have happened. Everyone who takes part in this experiment begins to feel a little more positive because instead of filtering for bad stuff, they are filtering for good stuff. They begin to notice what has been there all along, the small but significant events that feel good and contribute to our improved self-esteem.