National identity is one's identity or sense of belonging to one state or to one nation. It is the sense of a nation as a cohesive whole, as represented by distinctive traditions, culture, language and politics. National identity may refer to the subjective feeling one shares with a group of people about a nation, regardless of one's legal citizenship status. National identity is viewed in psychological terms as "an awareness of difference", a "feeling and recognition of 'we' and 'they'".
The expression of one's national identity seen in a positive light is patriotism which is characterized by national pride and positive emotion of love for one's country. The extreme expression of national identity is chauvinism, which refers to the firm belief in the country's superiority and extreme loyalty toward one's country.
National identity is not an inborn trait and it is essentially socially constructed. A person's national identity results directly from the presence of elements from the "common points" in people's daily lives: national symbols, language, colors, nation's history, blood ties, culture, music, cuisine, radio, television, and so on. Under various social influences, people incorporate national identity into their personal identities by adopting beliefs, values, assumptions and expectations which align with one’s national identity. People with identification of their nation view national beliefs and values as personally meaningful, and translate these beliefs and values into daily practices.
Political scientist Rupert Emerson defined national identity as "a body of people who feel that they are a nation". This definition of national identity was endorsed by social psychologist, Henri Tajfel, who formulated social identity theory together with John Turner.Social identity theory adopts this definition of national identity, and suggests that the conceptualization of national identity includes both self-categorization and affect. Self-categorization refers to identifying with a nation and viewing oneself as a member of a nation. The affect part refers to the emotion a person has with this identification, such as a sense of belonging, or emotional attachment toward one's nation. The mere awareness of belonging to a certain group invokes positive emotions about the group, and leads to a tendency to act on behalf of that group, even when the other group members are sometimes personally unknown.