3 How Groups Function – Group Decision Making

Group Performance and the Presence of Others

When tasks must be completed efficiently or under time pressure, people often form groups to get the job done. It is commonly assumed that groups outperform individuals, and this belief seems intuitive. After all, groups combine the resources, skills, and knowledge of multiple people, which should allow them to make better decisions and work more effectively. However, although groups can sometimes outperform individuals, this is not always the case. Group performance depends on a variety of factors, including task characteristics, member motivation, coordination, and social influence processes (Forsyth, 2019; Kerr & Tindale, 2004).

Social Facilitation and Social Inhibition

One of the earliest studies in social psychology was conducted by Norman Triplett (1898), who examined how cyclists’ performance changed depending on whether they raced alone or alongside others. He discovered that cyclists rode faster when competing with others than when racing against the clock by themselves. Triplett concluded that the presence of others can enhance performance. Later research supported this finding, demonstrating that people often perform better in the presence of others across many activities, including jogging, sports, weightlifting, and academic problem solving (Bond & Titus, 1983). This improvement in performance due to the presence of others is known as social facilitation.

However, performance does not always improve in group settings. Many people recall situations in which they performed worse when others were watching, such as public speaking or taking a critical shot in a game. When performance declines because others are present, this effect is known as social inhibition. Because the presence of others can both enhance and impair performance, it is important to understand the conditions under which each effect occurs.

Hazel Markus (1978) examined this issue by asking participants to complete both an easy task (tying their shoes) and a difficult, unfamiliar task (putting on a lab coat that tied in the back). Participants completed the tasks either alone, with another person watching, or with another person present but not paying attention. Markus found that participants completed the easy task faster but performed the difficult task more slowly when another person was present. Notably, whether the other person was actively watching did not matter; mere presence was sufficient to influence performance.

These findings align with Robert Zajonc’s (1965) drive theory of social facilitation, which proposes that the presence of others increases physiological arousal. This arousal strengthens a person’s dominant response, the behavior that is most automatic or likely in a given situation. When the dominant response is correct, performance improves; when it is incorrect, performance worsens.

For well-learned or simple tasks, the dominant response is usually correct, so arousal enhances performance. For complex or unfamiliar tasks, the dominant response is more likely to be incorrect, so arousal interferes with performance. Numerous studies support this explanation, showing that the presence of others improves performance on simple tasks but reduces both speed and accuracy on complex tasks (Bond & Titus, 1983; Guerin, 1993). Interestingly, Zajonc’s theory also applies to animals. Research has shown that dogs, chickens, ants, rats, and even cockroaches perform simple tasks better in the presence of others but struggle with complex tasks under the same conditions (Zajonc et al., 1969). Other explanations emphasize evaluation apprehension, suggesting that performance is particularly affected when individuals believe they are being judged or compared to others (Cottrell et al., 1968). For example, joggers ran faster only when spectators were visibly watching them, and athletes sometimes perform worse during critical home games due to increased pressure from supportive fans.

Process Gains and Process Losses

Thus far, we have focused on how group settings affect individual performance. A broader question is whether groups outperform individuals overall. Groups clearly offer advantages, such as combining knowledge, skills, and physical strength. In some cases, such as a NASA mission, a surgical team, or a musical ensemble, the outcome could not be achieved by individuals working alone. When group performance exceeds what would be expected based on individual abilities, this is known as a process gain (Steiner, 1972). However, groups do not always perform at their full potential. When group performance falls short of what would be expected from the combined abilities of its members, a process loss occurs. Group productivity can be expressed as:

Actual productivity = potential productivity − process loss + process gain
(Steiner, 1972)

Process losses often occur because coordination among multiple people is difficult, particularly as task complexity and group size increase (Forsyth, 2019).

Member Characteristics and Task Features

Group outcomes depend on both member characteristics and task features. Member characteristics include individual skills, motivation, and personality traits. For tasks requiring little coordination, such as assembly-line work, individual ability largely determines group performance. In contrast, tasks requiring high coordination, such as basketball or surgery, depend heavily on communication, cooperation, and shared mental models (Salas et al., 2015).

Tasks also differ in structure. Divisible tasks can be broken into subtasks, whereas unitary tasks must be completed collectively. Additive tasks combine individual efforts, compensatory tasks average them, disjunctive tasks depend on the best member, and conjunctive tasks depend on the weakest member (Steiner, 1972). Tasks may also be intellective, emphasizing accuracy, or maximizing, emphasizing speed or quantity (Laughlin, 2011).

Social Loafing

A major source of process loss is social loafing, which occurs when individuals exert less effort in a group than when working alone. In classic rope-pulling experiments, Ringelmann found that individual effort declined as group size increased (Ringelmann, 1913). Later research demonstrated that social loafing occurs across tasks and cultures and results from both coordination difficulties and reduced motivation (Karau & Williams, 1993). Loafing is more likely when individual contributions are difficult to identify and responsibility is diffused. Social loafing decreases when tasks are meaningful, individual contributions are visible, and effort is recognized (Latane et al., 1979). Women tend to loaf less than men, and individuals from collectivistic cultures loaf less than those from individualistic cultures (Karau & Williams, 1993).

Group Decision Making: Gains and Losses

Groups play a critical role in decision making in settings such as juries, committees, and governing bodies. Although groups benefit from multiple perspectives, evaluating decision quality is challenging due to outcome bias, the tendency to judge decisions based on results rather than the quality of reasoning at the time (Baron & Hershey, 1988). Cooperative groups generally outperform competitive groups and individuals on complex decision-making tasks (Johnson & Johnson, 2009). Group discussion stimulates idea generation, error correction, and transactive memory, whereby members remember who knows what (Wegner, 1987). When unique information is shared, groups make better decisions (Stasser & Titus, 1985). One major source of poor group decisions is groupthink, a phenomenon in which pressures for consensus suppress critical evaluation (Janis, 1972). Groupthink is most likely in cohesive groups with strong leadership, under stress, and when dissent is discouraged. Diversity reduces groupthink by introducing alternative perspectives and encouraging debate (Nemeth & Ormiston, 2007).

Cognitive Losses: Poor Information Sharing and Brainstorming

Groups often focus on shared information while neglecting unique knowledge, a bias demonstrated in hidden profile studies (Stasser & Titus, 1985). Traditional face-to-face brainstorming groups also under perform individuals due to social loafing, evaluation apprehension, and production blocking (Diehl & Stroebe, 1987).  Modified techniques such as the nominal group technique, Delphi method, and electronic brainstorming improve creativity by reducing these constraints (Paulus & Nijstad, 2019).

Group Polarization

Group discussion often leads members to adopt more extreme positions, a process known as group polarization (Moscovici & Zavalloni, 1969). Polarization arises through informational influence and normative pressures and is especially strong when group identity is salient (Isenberg, 1986). Groups frequently overestimate their effectiveness, a bias known as the illusion of group effectiveness, and tend to favor internally generated ideas, known as the not-invented-here effect (Forsyth, 2019). Improving performance requires awareness, motivation, clear goals, and effective leadership.

Clear, challenging goals improve group performance by increasing effort, coordination, and commitment (Latham & Locke, 1991). Diversity, when well managed, enhances creativity and reduces conformity, though it may also increase conflict and coordination challenges (Williams & O’Reilly, 1998).

References

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