Psychology Lecture Series: Self-Justification in Everyday Life
This video in youtube is posted by GRCCTV - a YouTube Channel from Grand Rapids Community College in Michigan, USA.
The whole lecture by Dr. Carol Tavris is available here.
Tavris emphasises how hard it is to make people realise they have made a mistake. Cognitive dissonance is an unpleasant feeling which people have when they are aware of two ideas that contradict each other. People are motivated to reduce dissonance by deciding WHICH of the two ideas is preferable. For example, think of a person who has the habit of smoking cigarettes. If this person finds out that this is unhealthy...they can choose: either stop smoking, or try to find a reason why the health risks are not real.
The question in this excerpt is “why would it be a useful thing to have this unpleasant experience?”