It should not be a surprise that we are often prone to overestimate our skill and underestimate our weaknesses. This can have the affect of trusting our instincts too much in the first instance and not understanding how our weaknesses impact others in the second.
Take for instance, an individual who is good at strategy. Because they have skill in determining strategy they can downplay the input of others, trusting their own analysis and conclusions. Yet, no one has the ability to think of all the consequences of any strategy or anticipate all the variables that can impact its success. Thus by not listening to others this leader is hurting the organization in their overconfidence in their own abilities. Their good ideas can fail because they overestimated their skill.
It is not unusual for highly skilled individuals to fail to bring others into the conversation - a weakness born out of confidence and a perceived lack of need of others. In their overconfidence they also underestimate the impact of not listening to those around them. Few things are more demotivating than to give helpful and valid input to a plan and to have their leader either ignore it or dismiss it as irrelevant.
In both cases the organization is served poorly - as well as people in the process.
Pride plays a role in this equation. We like to think the best of ourselves and our abilities but we should also be realistic. Healthy individuals with good EQ understand their strengths and weaknesses as well as the shadow side of both. That awareness allows them to compensate for their weaknesses and ensure that they don't over rely on their strengths. In fact, that is a pretty good definition of a humble individual. They have a realistic view of themselves.
How do we avoid these tendencies? One is to be aware of them and to ensure that we involve and listen to others. The second key is to solicit feedback from those we really trust. Feedback from others is an absolute essential part of growing our EQ as there are things we don't see about ourselves and never will unless others point them out. In order to hear feedback, however, we need to overcome our natural defensiveness.