Modern sociology and social psychology use the terms “in-group” and “out-group” to explain certain effects of interpersonal communication. The need to belong is probably at the foundation of the in-group versus out-group relationship in human mental perceptions. Ingroup versus outgroup perceptions are evolutionary or culturally developed stereotypes.

What Is an Ingroup?

An in-group is a group of people with which a person is psychologically associated and identifies himself or herself. The person feels that he or she belongs to this group.

Examples of such ingroups can be a person’s kin, own family, roommates, racial and ethnic groups, people of the same nationality—everything associated with the person’s social identity.

People use the term “we” to express themselves as the members of an ingroup. People of an ingroup tend to see similar values, opinions, norms, attitudes, and behaviors among the members of their ingroup.

People of an ingroup tend to like and tolerate each other, convey good will and help, and have a sense of solidarity. They feel unity and loyalty. They are cooperative and ready to support their ingroup members.

What Is an Outgroup?

An outgroup is a group of people that a person considers outside of his or her internal social circle. The person feels that he or she does not belong to that group. People of the outgroup can be the members of another tribe, another family, or people of another race, ethnicity, or nationality—anything not associated with the person’s social identity. These are outside groups.

People use the term “they” to identify others as members of an outgroup. They tend to see the values, opinions, attitudes, norms, and behaviors of members of outgroups as being dissimilar from their own ingroup. And they tend to dislike and avoid people from outgroups, showing them indifference, intolerance, or even hostility.

What Is Ingroup Bias? And Why Does It Matter in Love?

Individuals exhibit a positive attitude towards their own ingroup and its members. In-group bias is a person’s favorable predisposition toward people of his or her own group, their values, traits, attributes, and everything associated with their in-group. Such favoritism is especially pronounced in comparison to another group, which is known as “ingroup bias.”

Individuals exhibit negative attitudes towards their outgroup and its members. The tendencies to favor one’s own ingroup and its attributes are more evident than the tendencies to reject the outgroup and its attributes. Situations of intergroup contact activate both tendencies.

Members of an ethnic ingroup tend to exhibit ethnocentrism. And ingroup bias is a psychological mechanism that naturally works to support ethnocentrism.

An Evolutionary Perspective on Ingroup Bias and Love

Throughout evolutionary history, natural selection began to prefer “ingroup” prosocial dispositions and cooperation over antagonism. A set of human social traits and skills for favoritism arose and evolved. Neurobiological, paleoanthropological, and developmental studies are in support of his evolutionary conception (Hare, 2017).

Social bonds, care, and support within groups appeared to serve the evolutionary mechanism of human cultural evolution. Care was an active behavioral love for assisting others who were in need. People cared about those they loved.

In the early times of evolutionary history, love for kin, extended family, and one’s own tribal group evolved as a human survival mechanism. Later in social development, such community and family love evolved into ingroup favoritism and ingroup bias. This love in many cases was dutiful rather than free and voluntary.

“Love as a duty” was a type of love important for survival in the interdependent context of people’s lives (Karandashev, 2022).

The free romantic love became a luxury of life much later in human history. Some evolutionary theories, like Helen Fisher‘s, say that romantic love was one of the first things that brought people together to have children.

Actually, early people in a tribe were bound to love their kin and extended family (de Munck et al., 2016).