Dominant discourse is a way of speaking or behaving on any given topic — it is the language and actions that appear most prevalently within a given society. These behaviors and patterns of speech and writing reflect the ideologies of those who have the most power in the society.
Major theorists such as Michel Foucault and Stuart Hall supported this concept. They argued that relatively few people in a society hold authority. Those who do have power directly or indirectly assert their power on others within the society, thereby forcing those members of a society to adopt the actions and language of those in power. In this process, the prominent behaviors and ideologies eventually become the social norm.
A problem with dominant discourse is that it can become so ingrained within a society that few people challenge the norm. Without these challenges, few new ideas enter the mainstream. The society thus may stagnate and fail to progress. Even when people want to challenge the dominant paradigm, they may fail to do so if they lack the power to get their message or behaviors far enough into the public eye. People who want to change society may have to work at building a reputation before large numbers of the society will follow their example.
Two examples of major conflicts associated with challenges to discourse are the Civil Rights Movement and the Holocaust. In both these cases, the dominant paradigm involved discrimination against a particular group of people. Those in power during both these periods used open propaganda, as well as scare tactics, to assert and maintain dominance through the general population. A more general example of conflict related to dominant discourse is war of any type, although conflicts do not always escalate to the point of physical violence.
Even though the clearest examples arguably come from associated conflict, social norms can be positive for a society on some levels. One benefit of dominant discourse is that it provides one or more points of commonality between members of a society. This can help members of the society develop a sense of normalcy, as they have some predictability in terms of what they are supposed to do and say in different situations. It also provides people with a sense of belonging, because they are able to see that others are acting or speaking in the same way.
Dominant discourse is variable, meaning that discourses on different topics do not always come from the same individual or groups. For example, a church may provide a standard for prayer or preparing a funeral, while a health organization may provide standards for patient care and interaction. This means that changes to one dominant ideology don't always directly impact other discourses. In fact, members of society may remain ignorant of some dominant discourses unless they are in some way directly associated with certain groups, such as the general public being relatively unfamiliar with the meaning of many medical and legal terms.