Compliance refers simply to behaving in response to a request from another person or group even in the absence of a norm. whereas when compliance is shown to an instruction or order from a person in authority, such as parents, teachers, leaders, or policemen, that behaviour is called obedience.
Some of the reasons regarding obedience are :
a. People obey because they feel that they are not responsible for their own actions, they are simply carrying out orders from the authority.
b. Authority generally possesses symbols of status (e.g., uniform, title) which people find difficult to resist.
c. Authority gradually increases commands from lesser to greater levels and initial obedience binds the followers for commitment.
d. Many times, events are moving at such a fast speed, for example in a riot situation, that one has no time to think, just obey orders from above.