Attitude and behavior are two quite different things.
Attitude is a person's inner thoughts and feelings, while behavior is usually an outward expression of attitude, but the two are not always related.
Tell about the times your attitude and behavior have differed
For instance, psychopaths are people whose attitudes are composed of low morality.
However, this does not mean that they always commit immoral acts.
Psychopaths are usually intelligent, so they know that even though there will be no moral consequences for them, there will still be legal consequences to deal with.
This knowledge, in addition to their attitude, governs their behavior.
When a person's attitude and behavior differ, dissonance will likely result, and a change in attitude or behavior will be the probable outcome.
How attitude and behavior affect each other