Confirmation bias

In a variety of experimental settings, decision makers tend to notice more, assign weight to, and actively seek out evidence that confirms their claims and tend to ignore and not seek that which might discount it.

Confirmation bias may be the cause of self-perpetuating and self-fulfilling social beliefs.

To compensate for this natural human tendency, the scientific method is constructed so that we must try to disprove our hypotheses. See falsifiability. General thinkers and decision makers should consider opposing views and try to think about why they might be wrong in order to reduce overconfidence effects.