I think this issue touches on a number of aspects like self-worth, self-image and self-concept among others.
Undoubtedly people can place a distorted or disproportionate value on self and others based on education. It's mostly a problem of reference, how exactly do you value education and knowledge correctly?
Can we perceive, through some indications, if a person gives too much or too little importance to the education and intellectual formation?
Certainly, if the value they place on education/formation does not correspond to real tangible values. For example the janitor who thinks himself overall more qualified than the brain surgeon. Or the brain surgeon who thinks himself necessarily superior to others in areas where he has no expertise.
knowledge and its importance are not reflected in behavior
This is objectively wrong, for example the study of morals and ethics enables a person to positively change their behavior (as can the knowledge of healthy eating help to change dietary habits.) However, there's no necessary causal relation between knowledge and behavior.