Why a person behaves in a certain way?

Suppose your boss bawls you out for doing sloppy job on an insignificant project. To what do you attribute your boss's tongue lashing? Was your work really that bad? Is your boss just in a grouchy mood? Is your boss under too much pressure?
In assessing what a significant individual is like, people are particularly interest in learning why the person behaves in a certain way. This deeper level of understanding is vital if one is to make accurate predictions about the person's future behavior. After all, when you are looking for a roommate, you don't want to end up with an inconsiderate slab. To determine the cause of others behavior people, engage in the process of casual attribution.
Attributions are interferences that people draw about the causes of their own behavior, other's behavior, and events.
When people ascribe the causes of someone's behavior to personal disposition, traits, abilities, or feelings, they are making internal attributions. When they impute the causes of their behavior to situational demands and environmental constraints, they are making external attributions. For example, if a friend's business fails, you might attribute the failure to your friend's lack of business skills (an internal factor) or to negative trends in the economy (an external factor). Parents who discover that their teenage son has banged up the family car may blame it on. The carelessness (an internal attribution) or on slippery road conditions (an external attribution).