Introduction
The question “Who am I?” presses on human beings. Even people with severe amnesia appear to want answer this question—to understand who they are (Sacks, 1979). Social scientists from all disciplines recognize that people almost always answer this question with reference to other people (Cooley, 1992; Mead, 1934) and to groups of people (Tajfel & Turner, 1986). A person might answer this question, “I am a mother. I am a Muslim. I am Croatian.” People’s social identities —how they think of themselves in relation to others—are central aspects of people’s self-concepts and are also central to how moral people view themselves as being, to their close relationships, to the obligations and responsibilities they perceive themselves to have, and to their sense of connections to some or all other people.
A Brief History of Identities
Although all people and societies rely on social identities, identities have become more complex with modernity. In small and physically separate societies, people can have a personal relationship with each member of the tribe or community, and play specific roles within it (e.g., cook, daughter). In this case, nearly all identities are local (and communal). For example, aspects of one person’s identity could include her ability to farm or other skills, her connections to relatives, and her pride in upholding her culture’s morals. If small communities rarely have contact with one another, people would have little need of conceiving themselves as different from other groups, except on rare occasions of contact.
As the human population and societies have grown, people’s local identities remain relevant, but the concept of “local” begins to expand. For example, in European medieval city-states, people might identify as Florentines or Venetians but know only some of the people in their city. Because city-state identities had very much to do with people’s beliefs about whom they thought was appropriate to rule, urban identities became political identities (e.g., Strathern, 2015). When the Pope and various monarchs in Europe sought to govern Florence and Venice, political opposition made a city identity not only concern who one was, but also who one was not (e.g., King, 2003). Political contests over rulership and power have often led identification with one’s own group (the “ingroup” ) to extend to non-identification with outsiders (“outgroups ”).
One of the most important aspects of modern identity history is the invention of nationalism, which on each continent often had to do with consolidating smaller political entities into larger and imperial ones, or it had to do with resistance to empires by people sharing approximately the same language (Breuilly, 1994). Napoleon , for example, was able to recruit the psychological bonds of the identities that people had with their families and localities in the service of the new identity: being “French.” In doing so, he could convert people’s sense of loyalty to family and community, their willingness to give and sacrifice for the same, to loyalty and generosity and self-sacrifice for the nation . In doing so, Napoleon created a “fictive” collective identity, that is, identification with people who mutually imagine themselves to be part of a group, although they may never know or even indirectly interact with one another. True to its imperial origins, nationalism or chauvinism , the sense that one’s nation is and ought to be superior, is different than affectionate attachment or pride in one’s nation , which is called “patriotism ” (Kosterman & Feshbach, 1989). In our time, national identification and nationalism spur people to endorse the morality of violent actions that people might otherwise view as wrong, such as terrorism (Tausch et al., 2011) and killing civilians in war (Pratto & Glasford, 2008).
Identities can be formed in reaction to the formation of other identities. For example, people whom Napoleon attempted to dominate using French nationalism formed other collective identities based not only on having somewhat common languages, but also on having common enemies: German and Italian national identities (Breuilly, 1994).
Even broader concepts of identity have been set forth throughout much of human history. King Cyrus of Persia set human rights in Babylon in 539 BC , and his principles influenced other ancient civilizations and parallel part of the Universal Declaration of Human Rights . Ancient and medieval peoples established like principles, but issues about subordination (including patriarchy and slavery) in modern times were the focus of new political and philosophic thought just prior to American independence. Thomas Paine , the US Constitution , and the Napoleonic Code are among those articulating rights due to human beings or citizens. Holding a recognized national identity (rather than belonging to a royal or leading family or the upper class) became a means of making modern citizens equivalent in their protections from powerful others and equivalent in the protections and services their governments are obliged to provide. Naturally, tensions between rights of citizens and rights of humans and rights of nations remain. Regardless, from medieval times through the modern era, the possibility of social identities becoming more inclusive has grown both due to human contact and to new ideologies .
In parallel with the historical development of identities are the psychological possibilities for identities. Just as the collective that one could identify with has expanded beyond family and neighbors to ethnic or religious group, nation , and humanity, so too may any individual’s level of psychological inclusiveness of various identities vary from those of other people. People who include many categories of people within their concept of ingroup make the psychological boundary for their “ingroup” broad and weak. Such people are said to have high social identity inclusiveness .
Identities at Present
Rather than having broader identities, such as national identity, replace narrower ones, such as neighborhood identities, at present people can identify simultaneously with family, locality, nation , the world, or other levels of group inclusiveness (McFarland, Webb, & Brown, 2012). This is one reason that identification has become much more complex. In addition, because of the history of migration, of religious conversion, of imperial conquest, there are many identities that transcend region and national boundaries. For example, “Arabs” are represented on two continents and across what other people call “races” and are not ensconced in nationhood. Christianity and Islam have both spread to all continents from the same small territory. And people in parallel roles in completely separate societies (e.g., merchant, political leader) can view themselves as sharing a common identity . Anyone now has numerous group and role identities, and identities become more or less salient in different contexts. People who think of themselves as having a common identity with several other groups of people are said to have a more complex social identity (Roccas & Brewer, 2002).
Identities and Social Cohesion or Intergroup Conflict
Identities are important for societal cohesion for several reasons. People who think of themselves as having a common identity will be more generous to other members of their “ingroup,” (e.g., Tajfel, Billig, Bundy, & Flament, 1971), feel emotions on behalf of their ingroup (Mackie & Smith, 1998), including threat to the group (Stephan & Stephan, 2000). It is also the case that people who identify with “all humanity” are likely to work in international aid agencies (McFarland et al., 2012). In other words, having social identity inclusiveness will promote good will between groups. Indeed, groups who have solidarity with outgroups support autonomy for the outgroups (Stewart et al., 2016). A different likely way of measuring people’s tendencies towards group prejudice is to measure the breadth or narrowness of their social identity inclusiveness.
Alternatively, narrow ingroup identification is correlated with prejudice against outgroups. Indeed, one cannot have prejudice against a group without presuming there is a group boundary. The association of ingroup identification and prejudice against outgroup...