Do you have any colleague who constantly overestimates his/her capabilities? I am sure you have; we all have.
In psychology, this is a cognitive bias named Dunning-Kruger effect. It is usually measured by comparing self-assessment with objective performance.
The initial study was done by David Dunning and Justin Kruger and it focuses on logical problems, grammar, and social skills. They explained these results in terms of meta-cognitive abilities. The poor performers have not yet acquired the ability to distinguish between good and bad performances. They tend to overrate themselves because they do not see the qualitative difference between their performances and the performances of others.
In our day-to-day life, this effect has various practical consequences: from a risky-driving car behavior to choosing the wrong job, from starting to lead a project with limited resources to… deciding to not vaccinate yourself against COVID-19.
How can we confront Dunning Kruger's effect on the organizational environment? By being aware of the Gauss curve. In each group around 70% are average performant, 15% are high performant and 15% are low performant. Prepare some objective results and compare them with the statistics.
On the personal side, try to identify the factors that make this effect happen and what sustains it. Talk to a therapist if you can’t do it on your own. Work on your personal development because this helps you have a clear image of yourself and to like yourself with all your good and bad things. Live authentically and don’t try to overestimate anything just because it has to look nice.