When we speak of someone having a big ego we usually mean they have a grandiose sense of self importance. There are several factors relevant in making them so conceited, which relate mainly to their true level of self confidence. While it may seem as though someone with a bigger ego than others has a high level of self esteem, in truth, the opposite is generally so.
A person who's really confident has no need to shout about it from the roof-tops. People with big egos however, feel the need to inform everyone else they're special, in the hope the idea will rub off. Their frail sense of self causes them to work hard at being thought of as worthwhile, because secretly they fear they aren't.
People can become under-confident to the extent that their ego increases when they develop a great fear of rejection and abandonment.They try to cover up their fear by acting as-though they are super-confident. Most people who have a huge ego expect undying love and demand respect for this very reason, making having a relationship with them tough at times. Any sniff of possible rejection causes them to recoil in fear and lash out verbally.
Occasionally there are exceptions to the link between ego size and insecurity. This occurs when an individual remains stuck in a similar phase to that of a young child who hasn't yet learned they aren't the centre of the universe after-all. However, it's unusual for an adult to be able to get so far in life without cottoning on to the fact that they need the co-operation of other people to exist.
An intense fear of rejection and abandonment can come about most readily during childhood when an individuals personality is forming and their ideas and opinions are growing due to what they experience. If a care-giver rejects them or treats them badly they are more likely to grow up to fear a repeat performance from people they meet. This causes them to form an invisible emotional shield around themselves for protection.
Such ego driven emotional armour makes their hard exterior difficult to penetrate. This eases damage control, but also serves to block out love and positive healing experiences they could benefit from. Having a big ego thus becomes a lonely experience in itself.
People who have far smaller egos in comparison can range from those who are emotionally well balanced, to people who've turned fears of not being noticed into opposite types of behavior. Low self esteem can also cause individuals to miss out on life because they don't take part. Having a small ego can there-fore be just as detrimental as having a large one.