Ingroup bias is the tendency to favor one’s own group over other groups. Ingroup bias affects our perception of (and behavior towards) others, giving preferential treatment to the members of our own group while excluding other groups.

As a result, we tend to look down on people we don’t consider members of our group, even when we know nothing about them. Due to this, ingroup bias can lead to prejudice and discrimination.

What is ingroup bias?

Ingroup bias (also called ingroup favoritism) is a type of cognitive bias that causes us to categorize people depending on whether we share a common group identification with them. According to ingroup bias, people either belong to our ingroup (i.e., the same group as us) or an outgroup (i.e., a different group).

Group identification can stem from any characteristic that creates a sense of collective identity among people. This can range from sports team affiliation to nationality. This group identification can be temporary, such as an improv comedy troupe at college, or more permanent, such as religious beliefs. Therefore, one can experience ingroup bias in any situation where an individual’s group identity is prominent, like a workplace, school, or sports stadium.

Regardless of the nature of the group, we tend to like our ingroup members and dislike outgroup members.This feeling is accentuated when individuals feel that the value of their ingroup is being threatened.

Ingroup bias causes us to favor our own ingroup members, treat them differently, and be more willing to share resources with them. For example, we are happy to recommend someone from our ingroup for a job. Relatedly, we think of outgroup members as inferior, and we don’t wish to share resources with them (called outgroup bias).

We can observe this tendency at a larger scale among nations that are not willing to cooperate and share limited resources, such as water. When experienced in larger groups like countries or ethnicities, ingroup bias is referred to as ethnocentrism.

What causes ingroup bias?

Ingroup bias is caused by several factors. A number of theories can help explain why ingroup bias occurs:

• Realistic conflict theory suggests that ingroup bias arises due to competition between two or more groups for limited resources, such as jobs, money, or land. Whenever resources are at stake, people will favor their own group out of self-interest. The theory is called “realistic” because ingroup bias is based on an actual need for physical resources, as opposed to psychological needs.
• Social identity theory proposes that people favor their own group for psychological reasons, even when there is no competition for resources. In other words, ingroup bias arises naturally and instinctively due to our need to identify with a distinct social group. As soon as we categorize ourselves as belonging to an ingroup, and notice other people belonging to an outgroup, we tend to act and think in favor of our ingroup.
• Expectations of reciprocity. Ingroup bias has been observed in studies in which researchers sorted participants in an arbitrary way, such as tossing a coin or choosing between two famous paintings. This rendered the makeup of the groups unimportant. However, ingroup bias still occurred. One possible interpretation is that group membership can bring out strong ingroup bias, however random the group division is. Here, people cooperate with their ingroup members simply because they expect them to return the favor.

What is the impact of ingroup bias?

Ingroup bias cuts across social groups, settings, and cultures. It can be observed in children as young as three years old. Ingroup bias impacts our behaviors and attitudes in various ways. For example, it can cause us to:

• Take credit for the successes of other ingroup members
• Remember more positive than negative information about ingroups
• Be less critical of the performance of ingroup members than outgroup members
• Believe that our own ingroup is less prejudiced

Most importantly, positive behaviors from the ingroup and negative behaviors from the outgroup are attributed to stable group characteristics. On the other hand, negative behaviors from the ingroup and positive behaviors from the outgroup are seen as an exception.These are more likely to be attributed to temporary situational factors or the behaviors of specific individuals.

Perceiving ingroups and outgroups in this way is problematic. In its simplest form, ingroup bias can result in an “us vs. them” mentality. This can cause us to associate only with people who are similar to us and distance ourselves from those who are different. However, taking it to its extreme, ingroup bias can have serious consequences resulting in discrimination, xenophobia, and racism.

Ingroup bias examples

Ingroup bias suggests that group membership of both the witness and the perpetrator of a crime can have a significant impact on witness testimony.