The normative social influence involves conforming in order to be accepted or liked by a group, not necessarily because one actually believes the things one is doing or saying. This tendency is due to the fact that one of core instincts is to long to be in a social group of some sort. This comes into play because when a bunch of people get together and want to stay together there needs to be some degree of agreement as far as rules, morals, and behaviors because otherwise there would be issues among the members.
Over time people conform more and more to the ways other people do things. It becomes a social obligation to fit in and continue to do what others are doing. This does not just happen with friends or loved ones, it can happen with people you have never met. Overall, the people who are influenced the most by this concept have low self-esteem. These people tend to do just about anything to gain approval from others. Those who decide not to belong to the group are often called strange and deviant.
Conformist tendencies can influence all aspects of our lives including the election of our political leaders, moral values, food choices…you name it.
Example: Even though the boy secretly despises video games, he feigns interest on the playground when talk turns to the latest installment of Final Fantasy or Madden.
Here is an interesting article on the power of normative social influence: http://www.associatedcontent.com/article/1252544/normative_social_influence.html