Psychologists study groups because nearly all human activities (e.g., working, learning, worshiping, relaxing, playing, and even sleeping) occur in groups and these groups have a profound impact on our thoughts, feelings, and behaviors. Some researchers believe that groups may be humans’ most useful innovation that facilitated social norms and language development (Boyd & Richerson, 2005; Henrich, 2016; Aiello & Dunbar, 1993). Groups provide us with the means to reach goals that we otherwise wouldn’t if we remained alone. The advantages of group life may be so great that humans are biologically prepared to seek membership and avoid isolation.
Need to Belong
Humans have a powerful need to belong. Baumeister and Leary (1995) describe this need as “a pervasive drive to form and maintain at least a minimum quantity of lasting, positive, and impactful interpersonal relationships (p. 497)” and most of us satisfy this need by joining groups. It doesn’t matter if a person is from Israel, Mexico, or the Philippines, we all have a strong need to make friends, start families, and spend time together. Across individuals, societies, and generations, we consistently seek inclusion over exclusion, membership over isolation, and acceptance over rejection. People who are accepted members of a group tend to feel happier and more satisfied.
When people are deliberate excluded from groups the experience is highly stressful leading to depression, confused thinking, and even aggression (Williams, 2007). When researchers used an fMRI (Functional Magnetic Resonance Imaging) scanner to track neural responses to exclusion, they found that people who were left out of a group activity displayed heightened cortical activity in two specific areas of the brain, the dorsal anterior cingulate cortex and the anterior insula. These areas were associated with the experience of physical pain sensations (Eisenberger, Lieberman, & Williams, 2003). It hurts literally, to be left out of a group.
Identity and Membership
Groups not only satisfy the need to belong, they also provide members with a sense of identity, the universal construct that is shaped by our view of ourselves and how we are recognized by others (Chapter 8). Demographic qualities such as sex or age can influence us if we categorize ourselves based on these qualities. Social identity theory asserts that we categorize ourselves and form a social identity based on the degree to which we identify as a member of a particular social group (e.g., man, woman, Anglo, elderly, or college student) (Tajfel & Turner, 1979/1986). We don’t just classify ourselves, we also categorize other people into social categories. Social identity theory explains our tendency to favor an in-group (people we perceive to be like us) over an out–group (people we perceive to be different from us).
When we strongly identify with an in-group, our own well-being becomes bound to the welfare of that group which increases our willingness to make personal sacrifices for its benefit. We see this with sports fans who heavily identify with a favorite team. These fans become elated when the team wins and sad when the team loses. Heavily committed fans often make personal sacrifices to support their team, such as braving terrible weather, paying high prices for tickets, and standing and chanting during games.
People also take credit for the successes of other in-group members, remember more positive than negative information about in-groups, are more critical of the performance of out-group than of in-group members, and believe that their own groups are less prejudiced than are out-groups (Shelton & Richeson, 2005). Attitudes and beliefs about out-groups are often associated with infrahumanization which is the tendency to see out-groups as less human, or as having less humanity than in-groups (Vaes, Paladino, Castelli, Leyens, & Giovanazzi, 2004). We have seen this in history as a justification for genocide or ethnic cleansing (Castano & Giner-Sorolla, 2006). Though a strong group identity can bind individuals together, it can also drive divisions between different groups, reducing overall trust and cooperation on a larger scale. People are generally less likely to cooperate with members of an out-group (Allport, 1954; Van Vugt, Biel, Snyder, & Tyler, 2000).