You will probably by saying things such as "because it's wrong" or "I have been brought up not to". It is your conscience telling you it is wrong. We conform to rules because our sense of self-respect demands it, this process of social control is internal.
Internal forms of social control regulate our own behaviour in accordance with the accepted form.
Rational Ideology
This is an idea or belief to achieve social control. Your conscience, with feelings of guilt, anxiety or worry from within, guides you to reach a solution or follow laws and rules.
Tradition
It may be your own traditions, customs or norms that ensure you conform to the rules. Sometimes religion or culture or purely your upbringing ensures that you do not break the law, for instance not eating red meat on Good Friday.
Tradition
The culture to which we belong becomes part of us through socialisation.
We come to accept its values and norms as part of our identity.
For example believers follow religious traditions that have been raised in, such as Jewish tradition of sharing Shabbat.
Conforming to such tradition is an important way of affirming one’s identity and being accepted as a member of a particular community.
Internalisation of Social Rules and Morality
The internalisation of social rules and morality is working out what is the right thing to do and therefore knowing what is right or wrong upon social values. For example not eating all the biscuits but leaving some for others. Or not queue jumping but waiting in line for your turn and not cheating in an exam.
Superego
Our parents' rules and values that become part of our inner self or personality