What Sustains social norms and how they evolve?

http://128.118.178.162/eps/othr/papers/0309/0309001.pdf


Social norms or in other words the unwritten law of human interaction always intrigued me. Especially
our drives, meaning our reasons for conforming to these regulated and preconceived manners of interacting with our fellow humans is of critical importance for me to understand.
This study focuses on what sustains social norms and their evolution.

 Taking the act of tipping as a case study, it studies the motivational drives between choosing to either follow or  disobey a social norm.Unlike what one might suggest, tipping good or tipping of any kind is not motivated by a better service in future or a good service you have just received.
Looking at the history of tipping and the constant rise of tip percentages suggest that this specific social norm has not eroded(disappeared due to flux of social dynamics over time), suggesting the fact that it is not difficult or "costly" as the author puts it. In this case, there are two distinct kinds of drives,internal norms and external norms that influence our decisions. External norms result in a perceived peer pressure such as impressing, approval and disapproval of others by feelings of embarrassment, anxiety, guilt and shame and internal one that are consequences of empathy for the worker.
Through a conclusion driven by a theoretical model based on historical information, paper concludes that tipping in addition to just conforming to a social norm provides certain emotional benefits for the one who chooses to conform or not.